Sonic Adventure Autodemo

The Sonic Adventure Autodemo is a prototype version of Sonic Adventure, as the name suggests, the prototype is a collection of cutscenes and AI gameplay that was shown off by Japanese retailers to promote the game.

The disc was dumped and released to the general public on May 21, 2013 by Sonic Retro user OrangeFox. While not much can be seen normally, through hacking, a plethora of unused/beta content was found, some of which thought to be lost in time.

For whatever reason, the AutoDemo appears to de-synchronize on emulators. If one was to burn the image to a standard CD-R, only Sonic's demo would have synchronization issues.

Technical Notes

 * While the build was compiled in October, some stages were compiled in September, causing them to crash without hacking due to expecting a different 1ST_READ.BIN, as they're referencing stuff that has either been moved, or completely removed. This means the build is a frankenstein's monster of assets from different builds slapped together and shown off.
 * It's possible to hack the Autodemo to be playable.
 * While most levels are present, some levels are missing.
 * There's three test levels present, they take up Hedgehog Hammer's ID in this build.
 * The lighting is strange in some areas, this is because their respective PL/SL files are missing. So they either don't use lighting files, or use lighting files from other acts.

Demo Sequence


As this is an Autodemo, the game doesn't react to the player's inputs at-all, because of this, the demos and intro can't be skipped. The SEGA logo doesn't appear when first loading the game, but shows up normally before the opening movie after that.

The cutscenes and levels chosen to play throughout the demo sequences are different to the ones that play in the final game:
 * The second demo uses the Casinopolis cutscene with Sonic and Tails. In this version, it's dusk in Station Square (rather than night) and Tails' theme is playing.
 * The third demo uses the prison scene with Amy and Gamma. Due to the game lacking a demo featuring him because of this, Knuckles' theme goes unused in the demo.
 * The demos used for Amy and Gamma in the final are swapped in this version. Gamma's demo appears as the fourth demo and Amy's as the fifth.
 * Gamma's demo plays Red Mountain instead of Windy Valley.
 * Amy's demo plays Final Egg instead of Hot Shelter.
 * Big's demo starts in a different location.

Once the demo ends, this screen shows before the game resets.

Gameplay Differences
In terms of actual gameplay, the game is pretty close to completion, though there are some differences.
 * The player starts with 2 lives instead of 4.
 * The player doesn't lose rings when dying in demos.
 * The camera acts differently to the final.
 * There's more cuts present, in the final, most cameras zoom in or out.
 * The camera tends to clip below the floor.
 * The player-controlled rotation (by pressing either trigger button) is far slower than it is in the final, and has a tendency to invert itself based on the current angle.
 * Completing a level does not cause the level music to stop playing and plays the Chaos Emerald sound over the top of it. There's no results tally either.
 * The draw distance is smaller.
 * Instead of abruptly being taken to a black screen upon losing all your lives, the GAME OVER text simply displays on screen. Because the screen hastily fades out to black, though, it's only visible for less than a second.
 * Transitioning to another act is broken, as the lighting and music doesn't load unless the player dies or restarts the act, the textures sometimes also fail to load.

SEGA Logo
The SEGA logo is a lot darker and smaller than the one used in the final.

Title Screen
The title screen is much more simplistic in the version.

Mission Cards
The mission cards present in the demo are very different to the ones used in the final game. Even though the game only uses the Japanese versions, there are English versions of the cards in the game's files.

Life Boxes
In the AutoDemo, all Life Box icons face to the right with the exception of Sonic. This was changed in the final, where all the icons face to the left. The Tails, Knuckles, Amy, and Big icons' transparency issues were not fixed, though.

HUD

 * The HUD is slightly different in this version, there's a level part that was removed in the final, the ring is also slightly different.
 * Big's HUD lacks the darkened numbers and his weight value is also fixed to 12345g in the AutoDemo. His life counter in the AutoDemo is displayed in the top-right corner in the form of lure icons. The icon can still be found in the final.

Chao Icons
The Chao icon for stress was changed in the final.

"Chao in Space" Image
Instead of advertising "Chao in Space", the Casino map advertises "The Man 3". The billboard is used during the Egg Walker map in the final, though it was removed in SADX.

Pause Menu
The pause menu looks completely different, though it can't be seen without hacking due to pausing normally being disabled. An english version can be found in CON_REGULAR_USA in this build, and the final Japanese release.

Start!/Goal!
There are two images (stored in halves) reading "Start!!" and "Goal!!" in the AutoDemo's files. They seem to be some of the earliest files in the game, dating back to November 11, 1997.

Other

 * The Japanese font lacks anti-aliasing.

Music & Sound

 * All the music is stored in BGM.AFS, in the final, they're stored in separate ADX files.
 * There's a total of 29 tracks in this build, though not all of them are used.
 * Each song lacks a delay before it starts.

Unused Tracks
The following tracks are on the disc, but are never used. While Goin' Down!? (Speed Highway Act 2) and Theme of Chao (Chao Gardens) are used in their respective stages, they're never heard as no demo uses those stages.
 * Open Your Heart (Main Menu ver.)
 * Azure Blue World (Emerald Coast Act 1)
 * Windy and Ripply (Emerald Coast Act 2)
 * And... Fish Hits! (Big's Fishing)
 * Limestone Cave (Icecap Act 2)
 * Tricky Maze (Lost World Act 1)
 * Danger! Chased by Rock (Lost World Act 2)
 * Leading Lights (Lost World Act 3)
 * Crank the Heat Up!! (Final Egg Act 2)
 * Welcome to Station Square (Station Square)
 * Event: Strain (Cutscenes)
 * Event: The Past (Cutscenes)
 * Appearance: Knuckles (Cutscenes)

Changed Tracks
While some of the tracks are identical, most were changed.


 * The ring sound is used when grabbing animals, the intended sound is present, it's just not used.
 * The Chaos Emerald (1UP) Jingle is just Sonic 2's instead of a reorchestrated mix.
 * Various sounds from the Genesis Sonic games are used.
 * There's more Chao sounds than used.
 * Tikal's "This Way!" isn't voiced.
 * No voice clips are played after beating a level.

General

 * Characters don't have idle animations aside from standing still.
 * While all characters have pushing actions, only Sonic can do so for an extended period of time; everyone else will briefly push and then stop. Sonic is also the only character who actually has a moving sound implemented when pushing something as well.
 * Some textures are higher quality.
 * Picking up objects are broken, they will either crash the game, or be way off.
 * Sonic and Big are the only characters who can put down a held item without throwing it instead.
 * Held items cannot be shaken.
 * Drowning is not yet properly implemented: the numbers that appear are rather large and only appear for a fraction of a second. There is no drowning animation, and the game will instead just send the player back to the nearest checkpoint.

Sonic

 * His idle pose is different to the final, though it's still used in some cutscenes in the final, it's also slightly faster.
 * Sonic can actually lean left or right when standing on sloped surfaces, as well as forward and backward. In the final, he only leans forward or backward on slopes.
 * The way the Light Speed Dash works is completely different. Sonic kneels down before a blue sphere appears under your target, if the A button is pressed, Sonic will hit your target; when the B button is pressed, it becomes a normal homing attack. The system is really finicky - oftentimes the game will try to target thin air, and if there are no more targets in the area, Sonic will fly a very long distance. In the final, the Light Speed Attack autotargets and immediately hits a chain of nearby enemies when the player releases the action button after charging it.
 * The blue glow around Sonic when he uses one of the Light Speed skills has less green in it and is more translucent than in the final. It also has some intense flickering (though this could be due to quirks in emulation).
 * The Homing Attack's target is inconsistent. It also sometimes doesn't work on springs.
 * Some of his voice clips are more Engrishy.

Tails

 * His "tired" animation is broken, he just stands as he falls.
 * Tails' idle animation is faster.
 * He doesn't have an animation of jumping while holding an object.
 * Tapping the action button repeatedly will have Tails continuously spin-attack, complete with the dance animations like when he has the Rhythm Badge upgrade. In the final, his spinning is much more spaced out until you get this upgrade, which allows you to spin repeatedly by holding the action button down.
 * Tails doesn't make a sound when rolling.
 * Tails' textures for his mouth, nose, and eyes keep disappearing and reappearing during cutscenes.
 * Some voice clips for racing Sonic haven't been implemented yet.
 * The texture file for the Eggman that Tails races in Speed Highway has a trailing _1 in its filename (MRACE_EGGMOBILE_1.PRS) that is not in the final version. The textures in this build have minor differences from the final ones used.

Knuckles

 * Many of Knuckles abilities used in earlier builds can be found through hacking, though they've already been scrapped.
 * Knuckles can dig without the Shovel Claw.
 * The sound effect for gliding takes a bit longer to kick in - roughly a full second - after the gliding animation starts, and doesn't fade out.
 * Stars appear if Knuckles glides into a boundary. In the final, no particles like this are generated.
 * Trying to pick something up as Knuckles crashes the game.
 * Occasionally, punching Rhinotanks as Knuckles will also crash the game.

Amy

 * Has a high chance of crashing the game.
 * Her hammer doesn't appear while running.
 * Lacks effects.
 * Lacks hammer sounds.
 * Zero's sounds are entirely different.
 * Amy's dress flies further upwards when she falls.
 * If Amy gets targeted by Zero, a sound not present in the final plays.
 * The question and exclamation marks above Zero's head look different and far blockier from the final.
 * Zero's targeting reticule is a solid triangular prism - in the final, it's a triangular wireframe.

Big

 * Big's idle animation is much rougher in this build.
 * Big plays a voice clip while jumping.
 * If the action button is pressed, the game will crash.
 * Froggy's tail is much more visibly separate from the rest of his body than in the final.
 * Froggy has no struggling animations when hooked by Big - he just lazily swims along while hooked.
 * It's impossible to break the fishing line.
 * The camera doesn't zoom in if a level is cleared.
 * If a specific test map is entered, the game's coded to load "SAKANA.BIN", this was likely used to test the fish code.
 * No voice clips plays if Big catches Froggy.
 * If Big hooks something, "HIT!" doesn't appear and "And...Fish Hits!" doesn't play, although the music is on the disc.
 * The HUD's a bit rougher.
 * The text (Line [x]m) isn't vertically centered and the black area around it lacks rounded corners on the right side.
 * The line meter is placed in the middle relative to the text (in the final is to the right), and the UI itself is vertically centered on the screen instead of being in the bottom right corner.
 * The line meter doesn't change color according to how close the line is to breaking (it just stays the same shade of light blue the entire time), and the meter itself is visibly shorter than in the final.

E102 Gamma

 * Gamma is the only character who has a visible upgrade, the Jet Booster.
 * Gamma will quickly go into his gun-holding idle pose if he comes to a stop. This can also briefly be seen in one of his cutscenes.
 * When Gamma "runs" (crouching down and using the wheels on the back of his feet), there is a very loud high-pitched noise.
 * Has a different jumping noise.
 * Can jump while over water.
 * It's possible to shoot the Chao Garden animals.
 * Gamma's "shaking tree" animation completely clips through the tree he is trying to shake.
 * Has no sounds while breaking item boxes.
 * Gamma's gun textures are separate in this build (E102ITEM.PRS).

Tikal

 * While not used in any cutscenes or the Autodemo, her model, animations and textures are present, suggesting work had started on the Past.

General

 * There's a compressed version of the file used to load FMVs in this build (MOVIE.PRS), if the file is decompressed, it's revealed it references "SAOP600.SFD", while the used version refers to "SAOP1006.SFD", suggesting the original intro was 6 minutes. The unused compressed file is three days older than the uncompressed file.
 * The intro is 320x240 stretched to 576x480, with black bars to make it 640x480.
 * A higher quality version is used in SADX.

Differences

 * The cars are in the second and third shots are arranged differently, some people are also missing.
 * When the water comes out of the manhole, it's misplaced slightly at first, but then corrects it-self.
 * There's no fog in some scenes.
 * The waves near the end are slightly different.
 * Tails' expression near the end is different.
 * Gamma's numbers aren't present in any shot.

Test Levels (STG00)


There's three test levels meant to test the game's physics engine, though only PRACTICE 3 loads in-game. They were replaced with Amy's Hedgehog Hammer in the final.
 * They all completely lacks references to textures, likely to reduce load times.
 * Very little models are used.


 * PRACTICE 1 is used for very basic physics, there's also transparent blocks, the smallest one can be pushed.
 * PRACTICE 2 is used for more advanced physics, there's also a Pinball-Rail like area.
 * PRACTICE 3 is used for automated paths, though invisible ladders for Sky Deck can also be found.

1 = The original Japanese says "nakkuruzu desu desu" here.
 * At the end of the stage file are a few Japanese strings, when translated, they read.

Emerald Coast


Emerald Coast loads as it's required for Big's demo.

General

 * The level as a whole has dimmer lighting than the final. This is especially obvious at the beginning of Sonic's Act 1 when you look at the sand texture.
 * Lacks death planes.
 * Missing many details.
 * No act transitions exist.

Act 1

 * Sonic spawns in mid-air above his starting point, when he lands, the camera is different.
 * The beginning is very empty, only trees.
 * There's two Rhinotanks near the bridge instead of one.
 * Only four springs crossing under the bridge at the beginning instead of five. Some are also floating without supports. Springs also have a tendency to not launch you far enough.
 * No rope barriers on the platforms after the springs. No swinging spike ball in the middle of the area after the springs either. There's also only one spring used to get * * * Sonic back up to the bridge before the loop; in the final, there's two.
 * The first loop only has one dash pad. It also has a very different camera angle than the one in the final:
 * There are extra Rhinotanks before the jump ramp.
 * No item box around the back of the island with the jump ramp.
 * There is a Kiki instead of a checkpoint after the jump ramp:
 * There are extra dash panels present in the small area Sonic runs through after the jump ramp.
 * The checkpoint before the whale chase is placed right after the second loop, rather than just before the chase itself.
 * The second loop is broken, Sonic loses all momentum even with the dash panels.
 * The camera at this point is broken, as tends to clip below the floor, it's also facing the wrong way when fixed.
 * The whale and its chase section is completely missing.
 * No Kiki in a tree next to the second spike wall
 * Three "?" ring boxes are missing behind the large island near the lighthouse.
 * There is an extra spring added while climbing the large island.
 * There are fewer floating islands around the Life box near the end of the Act than in the final.
 * You don't get picked up by wind if you fall down one of the holes around the lighthouse.
 * There are Kikis on the rails near the lighthouse.
 * There is no Kiki above the act transition point.

Act 2
Act 2 is even less complete, missing most objects, later points of the level are completely empty. Springs at the upper path do not work correctly consistently and have a different spring path.
 * Sonic starts Act 2 facing away from the path.
 * There is no back wall at the entrance, just a hole in the geometry leading to a bottomless pit.
 * The waterfall's missing.
 * The arrangement of rings on the wall Sonic can run on is different, there's also no Speed Shoes.
 * There is an extra set of rings after the first checkpoint that doesn't appear in the final.
 * The last two checkpoints are missing.
 * The ring layout on the wall near the start is very different. Only small single lines lower down. There is also no speed shoes box on this wall either.
 * No objects in the higher tunnel accessed from the wall.
 * No life box or dash panel after the Springs in the upper path - only rings.
 * Rings entering the water in the lower path are in midair.
 * The Sweeps are at the bottom of the pool rather than on the surface. There are also 3 of them, with the final reducing this to 2. There are also no air bubbles or platforms in the water:
 * No circle of rings after the pool.
 * No ring box in the spike wall area.
 * There is a 10-ring box after the spike walls that has been replaced by a Kiki in the final.
 * Very few rings before the big loop.
 * No dash panel after the big loop.
 * Jump ramp does not work correctly, you hit the invisible wall at the edge of the land.
 * The area with the large steps in the final lacks the objects, so it's a smooth hill. This can still be seen in the final from a distance, though.
 * There is a Kiki on a small tree in the step area that is not there in the final.
 * The camera in the tunnels going up to the checkpoint area snaps to locations instead of gradually travelling to them.
 * No dash panels in the large hill after the checkpoint.
 * The jump panels are the only object present in the area they're found in. The boxes, Kikis and Tikal are missing.
 * There is no spring after the jump panel area to get into the area with the third panel in the final.
 * The alternative route to the jump panels (Spring) does not work. The spring sends you to your death.
 * Jump panel order is different. The final's second panel is not there, meaning there's only 4 panels.
 * The last panel is slightly to the right of the platform you're going to, rather than directly above it. There are also no Spike Walls present.
 * The automated path for the last loop is absent.
 * The end island is completely empty, no objects present.

Act 3 (Big)

 * Big spawns in the secret area, the entrance/exit is also blocked off.
 * As the is Big's area, Froggy also spawns here.
 * If Big's position is hacked to where he spawns in the final, there's some leftovers from Sonic's Act 1
 * The island for the cutscene, along with the leftover objects, are present.
 * Interestingly, this act seems to be based on a later version of Act 1! As missing details (sling bands), are present.
 * Strangely, the camera file is blank.

Windy Valley
The Windy Valley in this build is actually the original version of this level seen in many pre-release screenshots and footage. At the time of this build, it is already scrapped: it is missing (most) textures, music, and unique sound effects, and no effort has been made by the developers to make it remotely functional within the game itself. It cannot be loaded in-game normally due to expecting a completely different version of 1ST_READ.bin - the game will jump to an invalid pointer (of which there are many) and crash, and the stage files themselves refer to numerous items that either have been moved or do not exist. The game doesn't even have an entry for it in the list of level textures - the list skips from Emerald Coast to Twinkle Park.

However, through intense hacking of the level's pointers and memory locations, large swaths of it can be restored - its objects, object programming, and event programming are all intact but are buried in locations different from the 1ST_READ.bin in this build.

General

 * The object SET file is one of the oldest files in the build, being modified on 7/28/1998.
 * The number of objects this version of the level has is 115; the final has 79. Many of these objects were scrapped or replaced with newer versions in the final version of the game.
 * The level file has a larger file size than the final version.
 * There are only level object files for Sonic, but there are initial coordinates for Sonic, Tails, and Gamma, who all visit Windy Valley in the final. Sonic has coordinates for all three acts and Tails has coordinates for only Act 3, like in the final - however, Gamma has coordinates for all three acts despite only visiting Act 1 in the final game. Gamma's initial coordinates values are the same as Sonic's, so he starts in the exact same places.
 * Despite the above, E-103 Delta's model is included in STG02.PRS, indicating that some work on Gamma's version of the level was made.

Act 1



 * Sonic has a camera for this stage, but it acts weird as it seems to have been created when not many types existed.
 * There's around 1800 objects, though the game limits itself to 1023.
 * Leon is loaded, but never used.
 * Amy and Big don't have starting positions even though they were seen in Windy Valley in earlier builds.
 * The tornado is loaded through a function in 1ST_READ.BIN, unlike any-other object in the game.
 * If the player attempts to goto Act 2 the game will crash, see below.

Act 2

 * It completely lacks CAM data.
 * Act 2's LandTable pointer is NULL, and the LandTable itself is missing, though the meshes for it do exist.
 * There is data for the tornado "enclosure" that wraps around the level proper, along with subroutines to load it.
 * There's a lot of debris flying around in this build.

Act 3



 * Unlike Act 2, the LandTable is present.
 * Only Sonic has an SET file.
 * This Act also lacks CAM data.

Objects
Most of the objects are entirely different, with a few exceptions.
 * BANEIWA is the imfamous Blue Spring object, it can be seen in prerelease footage.


 * E-103 actually makes it into the final game! But it isn't used due to the lack of a SET file for Gamma. It functions nearly identically, except once it flys, it won't come down making it impossible to beat.
 * There's a lot of decoration objects in this build, most of which are animated, most objects in the final aren't animated to improve performance.
 * TSPRING is another spring object, it's only used in Act 2.
 * LAUCHIN is yet another spring object, though it functions a bit differently. It retracts very slowly after the player has hit it.
 * TRAMPOL was replaced with a different version in the final. The game also crashes if Sonic enters his dynamic animation.
 * ROCK are floating objects, they're mostly used in Act 1 and 3.
 * There's three bridges, but their models are missing, though the collision is still there.
 * WELE is an elevator like object, it's only used in Act 3. The object moves down a certain distance when the player goes inside.
 * ELeon actually makes it into the final game, even the textures are intact! It functions identically, though it's collision is broken. It goes unused due to the lack of a SET file for Tails.
 * T_RAFT1 is a small rock, if given the right parameters, it will float up and down.
 * T_RAFT2 is a interesting object, it moves up and down on its own, and it has a curved shape. It's used in Act 2.

Oddities

 * There's a trail of blue spring objects in Act 1 that just leads to an empty area, there was likely a item box at one point.
 * In Act 2, the game has two blue spring objects laid on top of eachother.

Twinkle Park
Twinkle Park is very intact in this build, the textures and LandTables are present.

General

 * Very few differences in geometry.
 * Amy and Big's files are missing.

Act 1

 * The beginning floor textures are different.
 * The bumper car ring at the beginning of the stage has a massive item (it is not an object and lacks collision entirely) in the middle of it.
 * The walls on the side at the beginning are slightly different.
 * The floors before the double loop are miss-placed slightly.
 * A camera file, CAM0300.BIN, exists, lacking the character suffix. It's dated July 30th, the used one is CAM0300S.BIN, there's little differences.
 * The objects don't match up with the geometry, this is a leftover from the Tokyo International version, as ring layouts match up with the video.

Act 2

 * The geometry seems identical to the final's.
 * The cameras at the beginning of the act is different, one of them is also broken.
 * The camera locks after the roller coaster.
 * This is one of the more empty acts, most of the objects are before the entrance to Amy's act 3.
 * The Ferris Wheel's ground isn't solid.
 * Amy's entrance to Act 3 isn't blocked off, the springs leading up are also missing.
 * The only objects after that point are the rotating roofs. This also means the capsule doesn't exist.

Act 3

 * The end of the room of mirrors is different - in the final it makes it look like Amy has to walk into a reflection, whereas here it ends in a straightforward manner.
 * There's only one object in the SET file, a lonely trapdoor at -80, 88, 194.
 * The cameras that are far below the stage are present. The used ones however, aren't.

Lost World


Lost World is pretty similar to the final in-terms of geometry, though it still manages to show changes.

General

 * Crashes due to expecting a different version of 1ST_READ.BIN.
 * Like Windy Valley, it doesn't have an entry in the level textures, it skips from Red Mountain to Sky Deck.
 * The level primarily differs in object layouts more than geometry changes.

Act 1

 * There's a blank camera file present (CAM0700.BIN). It has a date of July 30, 1998. As such, the camera is yet again very broken, tending to show the outside of the level geometry instead of the level itself, or getting stuck in the floors.


 * The camera very jankily follows Sonic down when he falls into the stage. In the final it is much smoother.
 * The first room of the level has an open ceiling that is instead blocked off in the final.
 * There are two Boa Boas in the first room. In the final, there is only the one that is immediately seen when the level starts.
 * There are flaming arrows before the circular section.
 * There is a missing booster in the tunnel before the circular section.
 * The circular section has no rings to pick up within it.
 * The lines of rings in the tunnel after the circular section have crooked placement.
 * There is no item capsule in the air when Sonic leaves the second tunnel.
 * There are no platforms after the tunnel.
 * The first checkpoint is missing.
 * The camera has serious issues trying to handle the water serpent room, particularly when the player enters it.
 * There are no stone pillars in the middle of the water serpent room.
 * The exit to the room is already open: there are no colored switches to open the door, nor is there a display for them above the doorway.
 * To the right of the water serpent room entrance, there is a Boa Boa. In the final, there are just breakable stone boxes.
 * To the right of the water serpent room entrance, the large barrier/platform is misplaced - it is slightly floating above the floor. As a result, Sonic can walk under it.
 * The platform with the first switch is entirely missing. Instead there is a platform floating in the air that Sonic can't reach until the water level is raised.
 * There is a set of inverted spikes after the platform. In the final, there are floor spikes at this location.
 * There is another set of inverted spikes and a large L-shaped structure that leads nowhere. In the final, there is nothing here but a row of floor spikes.
 * Past the large L-shaped structure, there is just a stretch of bare floor. In the final, there are floor spikes, rings, and breakable box objects.
 * The platform that in the final would have the blue switch to open the exit instead has a water level switch in its place.
 * The camera tends to clip through platforms and other objects while Sonic rides the serpent.
 * The second water level switch in this version has a Leon guarding it. In the final, this particular switch has no enemies nearby.
 * There is an odd H-shaped platform directly in front of where the second water level switch is. It has no enemies or other items.
 * Sonic can just jump to the door with no trouble after the water level is raised a second time.

Act 2

 * The camera has a tendency to kill the player often in this section.
 * The entrance before the mirror section has a gate object that continuously moves up and down. It has a tendency to push Sonic through the floor and kill him if he stands under it. In the final, there are two (completely solid) doors that open when Sonic gets close to them, and they have a more fleshed out opening animation.
 * Only the small, movable mirrors are present, and there are no large mirrors to guide them to. Because of this, there is no way to exit out of controlling one of the mirrors without restarting from a checkpoint from the pause menu.
 * Because the mirror puzzles can't be completed, the snake torches on the sides of the path cannot be lit.
 * The path directly after the first mirror is missing a Sol and the flaming arrows that come after it.
 * The path directly after the second mirror is missing a set of floor spikes between two platforms.
 * The path directly after the third mirror has a Boa Boa instead of a Sol. Of note is that in the final, this is still the case for Knuckles' object layout, hinting that his final object layout is a modified version of the one in this build.
 * The platform that has the fifth mirror inexplicably has a flame pillar object placed next to it in the water that's under the entire room.
 * The path directly after the fifth mirror is longer here than in the final: it has an extra platform with an extra mirror and the path continues on another platform placed at an angle from it. It has a Boa Boa and no flaming arrows. In the final, this is just a single long platform with flaming arrows, leading immediately to the trail of rings needed to continue.
 * The path of rings is a bit more crooked.
 * There are no rings on the water slide after the act's second checkpoint.
 * The three platforms between the sequence of springs at the bottom of the waterfall are missing entirely.
 * The entrance to the boulder chase is missing the door object that temporarily blocks it off in the final. There is another one of the moving gate objects directly after the checkpoint, despite it not being tall enough to accommodate the entrance without it visibly floating when it gets halfway through its animation.
 * There are no item capsules during the boulder chase.
 * The small pillar decorations on the ledge Sonic lands on directly after the boulder chase are placed (brokenly) at 45 degree angles inward. In the final, they are straight up and down.
 * There is another one of the moving gate objects at the entrance to the next hallway, and the end of the hallway is missing its door. In the final, both ends of the hallway have door objects.
 * The checkpoint in this hallway is missing.
 * The small hut at the beginning of the wall tile section has a pillar at the top of it that extends all the way to the ceiling. In the final, it lacks this pillar and also has a ray of light shining down on it.
 * The entrance directly into the wall tile room has another one of the moving gate objects.
 * The switches that move the wall tiles have lights shining up from them.
 * There are three switches placed on the ground floor on pillars of varying heights. In the final, there is the one on the ground, with the others placed in different (higher) places in the room. The placement in this version seems to hint that they were still debugging the tile puzzle.
 * All the enemies are Boa Boas - there are no Sols.
 * The panels start out in the connected positions needed to proceed.
 * The panels never light up and become walkable even when connected. As a result, this level cannot be completed via normal play.
 * The panels move in less random ways in this version, being relatively connected during every move.
 * A platform from what would be the second switch the player comes across in the final is missing here, though there is a very obvious gap in the wall tiling where it should be.
 * The path directly after the first rotating cube platform is a raised platform with floor spikes and a platform equal in elevation to the floor in the room ahead beside it. In the final, it is all just a flat platform with flaming pillars coming out of the walls beside it.
 * The checkpoint in this room is missing.
 * The room where the checkpoint would be only has Leons and a circle of rings. In the final, there are two Sols, some pillars, some breakable box objects, and an item capsule.
 * The final platform before the tunnel that leads to the exit has flaming pillars coming directly out of the walls. In the final, they come out of a thin ledge, which allows the player to hug the wall and jump over them.
 * The tunnel Sonic has to jump into has no rings leading into it.
 * There are no breakable box objects before the second jump down.
 * The switch that spawns the trail of rings to the exit is missing, which naturally means that the act is unable to be completed in normal play.
 * The platform that the switch would be on is just one single platform here, with a small pillar at each corner, behind a full row of floor spikes at the edge of the area. In the final, it's three platforms arranged, with two pillars that the rings would spawn between, and the floor spikes are just far to their respective sides.
 * The end of the level has no end capsule or trigger to end the level, adding yet another reason why the level cannot be completed in normal play.
 * The entrance to the mural room has no wall blocking it, so it leads into the void outside of the level geometry. The ceiling also has no collision.

Act 3

 * Aside from the capsule, the level completion object and the door behind Sonic being missing, it's the same as the final.

Sky Deck
Sky Deck crashes due to expecting a different version of 1ST_READ.BIN, though it's similar to the final.
 * The Dark Sky texture when the ship goes below the clouds is missing.

Act 1

 * Act 1's lighting files are present, but are identical to the final.
 * It's geometry is identical to the final.
 * There's no alternates route where the second checkpoint is.
 * The second dash panel will likely push the player though the floor.
 * The rings right after it are on the ground, in the final, they're slightly in the air.
 * A speed shoes monitor is missing.
 * An area at the end is missing.
 * The spikeballs near the end move much slower and don't move up and down.
 * There's a regular shield in-place of a lightning shield.
 * The player doesn't need to destroy the cannon to progress.
 * Tails' version of the stage lacks some boosters.
 * Tails' version doesn't include the Capsule, instead it's the rocket from Sonic's version. Though the cannon isn't present making it impossible to beat the stage.

Act 2

 * The level geometry, while very close to the final, has a few alterations, particularly in the final area of the act. The area where you have to fire rockets at the large cannon is missing its two rocket platforms, which indicates that part of the level was a late addition.


 * The textures are slightly different, particularly for decorative parts of the stage geometry the player would be hard-pressed to see in normal gameplay.


 * The beginning is missing a lot of objects.
 * The pole Sonic grabs onto is missing.
 * The jump panel trail is missing.
 * The wing doesn't break off. There's also ladders instead of cannons.

Act 3
The level geometry, while very close to the final, has a few alterations:
 * The offshoots in the latter part of the stage (where Knuckles can enter to find shards) have shorter hallways in this version.
 * This version has symmetrical tube structures in the first part of the stage, over the first area the player lands in after ascending from the beginning of the act. In the final, one of these is missing.
 * There is only one set of lattices bordering the stage geometry in this version. In the final, this is doubled.
 * The textures for the square-shaped holes that Knuckles can dig into in his version of the act are far darker than in the final.
 * Object OCARRIER3 is used in this build. OCARRIER is meant to add extra details to the stage, but for some-reason, OCARRIER3 was removed from the stage in the final.
 * The rings have a more wonky placement at the beginning.
 * The dash panels at the beginning are completely missing, instead, there's a bunch of Unidus'.
 * The claw Sonic grabs onto is missing.
 * Many rings near the end aren't present, the spring also isn't here. This makes it very hard to progress.
 * The button is rotated incorrectly.
 * The invisible walls surrounding the capsule aren't present yet.

Casinopolis
Casinopolis is less complete than other stages, only including rough, early models similar to the Test Levels.

General

 * All maps completely lack references to textures.
 * All the SET files are blank, except for Act 3 (Sonic's Pinball), which has all the object defined.
 * Even if the 1ST_READ.BIN pointers are fixed, the game will crash, something must be wrong with the LandTables.
 * Tails' starting coordinates aren't present.

Act 1

 * The most interesting difference with this act (aside from the rough model), is a 3D Bunny Girl that was replaced with a Cow Girl Billboard in the final JP release, a bar beside it was also removed.
 * The second pirate ship is rotated differently.
 * There's two poles present in the Chaos Emerald room.
 * The room near the pirate ships is a slightly different shape.
 * Night's pinball entrance is missing.
 * The shower room is just a hole in the geometry.

Act 2
Act 2 seems to be identical in-terms of layout, though the unused long path in the final is present.

Act 3
Sonic's Pinball seems to be nearly complete, though there still some differences.
 * There's a complete tower in the right side of the table. In the final, only the bottom of its geometry remains.
 * There is geometry for more tower-like structures in the left side of the table. In the final, these are not present.
 * The dividers where the ball enters the table proper are narrower and less round than in the final.
 * The prototype table is missing two squareish structures near the middle of the table that are in the final.

Act 4
The model for Night's Pinball is completely different to the final.
 * This is actually based on the prototype version seen in some of the earliest screenshots available.
 * The model forms a long curved shape, it seems like Sonic was meant to get to the top.
 * The object list has a few unique objects not in the final.

Hot Shelter
While it doesn't have a level ID, Amy's starting coordonnants do exist.

Adventure Fields
The Adventure Fields sends the player back to the Title if loaded, to prevent this, set 0x8C768B38 (0x2C768B38 for Demul) to 4. Only the ones for cutscenes have the textures.

Station Square
By extracting the Station Square geometry, it is possible to see some differences:

Casino

 * The train station has no entrance.
 * You can't ascend the stairs at the train station properly.
 * You can walk along the train tracks.
 * The front of the hotel has no collision.
 * The billboard does not advertise Chao in Space. In its place, there's an advertisement for "The Man 3", though only the top-left of it is shown.
 * There is a poster above an awning in the alley that is not in the final.

Station

 * The Twinkle Park entrance is completely different. Interestingly, it lines up with the main Twinkle Park stage's castle motif better, suggesting that the kart track the level opens with came later and the exterior was updated to have a more futuristic feel to match.
 * The sewer area where Big obtains a lure has a much lower ceiling.
 * The dock which leads the player to the Egg Carrier does not exist. This may suggest that the player originally wouldn't be able to go back to the Egg Carrier after completing the game.
 * The Hotel has a "Hotel" sign above the entrance.
 * The slope between the street and the beach is smaller.
 * The "CYBER-NET INC." building is much taller than in the final.

Hotel

 * The player doesn't have a spawn point.
 * There is a chandelier that doesn't appear in the final.
 * The ladder shown in some prototype pictures still exists.
 * The pool area has different placement of the chairs and tables.
 * The tables and sunbeds by the pool are arranged differently than the final.

Misc

 * The only difference in the City Hall area is that one door on a building next to the sewer in the City Hall appears to be reflective (Glass) instead of using a texture like the final.
 * The water is present, but is invisible due to the incomplete map.
 * The player will spawn out of bounds in the Twinkle Park entrance area.
 * The files for the lighting are present (and no different to the final game's versions) but 3 are unused, curiously the Hotel Entrance uses its lighting, even though the level it-self is unused.

Oddities

 * There's an alternate set of camera files in this build (CAMSETSS##S.BIN), while used ones are CAMSS##S.BIN. Oddly, the used ones are older than the unused ones, and contain nothing but blank data. Only CAMSETSS00S.BIN has data.
 * All the SET files actually have data in them, unlike Mystic Ruins (see below).

Mystic Ruins
Mystic Ruins crashes due to expecting a different version of 1ST_READ.BIN, though by extracting the geometry, minor differences can be seen.
 * The monkey cave in the train area is a slightly different shape to the final.
 * The light speed attack ledge on Angel Island is missing
 * The bridge on Angel Island is also slightly different to the one in the final version. The one connecting to the rest of the area is also a part of the level it-self instead of an object.
 * There's a few more rocks on Angel Island.
 * Act 3 crashes level viewers.
 * All the SET files are blank, same for the CAM files.
 * The maps references a few textures.

Egg Carrier
The Egg Carrier has some notable changes to its adventure field in the form of object layouts (only the rear transformed deck and the prison can be seen in-game, though) as well as some minor geometry edits. The changes listed here to the front/back of the ship are present in both the untransformed and the transformed version.

Front Deck

 * Item boxes below the Captain's room containing "?" rings.
 * No spring at the back of the area where Chaos 6 is fought.
 * There are many circles and lines of rings present around the deck.
 * The Monorail is missing.
 * The springs in the landing area point straight up instead of at an angle.
 * There are no hint boxes at the area where Chaos 6 is fought.
 * The center of the Chaos 6 arena sticks out, unlike the final where it's flat. The low-detail version viewed from the back of the ship when transformed actually makes it into the final, but it's difficult to see.
 * The boxes around the area where Chaos 6 is fought are in different locations and contain items including two Speed shoes, a life and a Ring box.

Rear Deck

 * Loads the proper textures and objects, as Sonic's cutscene is set here.
 * Behind the swimming pool building is two "?" ring boxes and a Life box. In the final, this was changed to two 10 Ring boxes.
 * There is a cannon on the middle platform of the large tower that isn't in the final.
 * The large, spinning platform at the top of the tower does not appear, nor does the 10 Ring box slightly below it.

Main Deck

 * Loads textures and objects due to Gamma's cutscene taking place here.
 * Monorail is missing.
 * The lighting is slightly less greener than the final.
 * The doors have very bright lighting.
 * There are 5 maids in the bottom area. In the final, there's 3.
 * There's no puzzle outside the Chao Garden door.
 * There are rings and two 10 Ring item boxes at the back of the room that were removed in the final.
 * There are no hint monitors.
 * The robots moving along the left and right side of the upper level are missing.
 * The pods, elevator and arches going over the room are not solid.

Prison

 * The lighting is different to the final. There is no fog.
 * Loads textures and objects due to Knuckles' cutscene (instead of playing the Knuckles fight scene for the third demo, it plays Amy's cutscene with Gamma instead) taking place here.
 * The middle cell contains a "?" Ring box and a Life. In the final, these were replaced with the black Chao egg.
 * The cells make no sounds when being opened.
 * There is no lure upgrade in the rightmost cell for Big.
 * The fans below the floor spin slightly slower.

Misc

 * There are no items on the upper level of the pool area.
 * Sonic's cutscene will load if the player tries to enter any map for the Egg Carrier's exterior as Sonic.
 * The entrance to the living quarters is on the right side of the room, rather than the left.

Bosses
All boss levels except for Chaos 2 will crash the game if the player attempts to access them through the level select. This could be because all boss levels except for Chaos 2 also lack their actual bosses.

Chaos 0

 * The doors windows are missing from the LandTable, the object layout is also the same as the Tokyo International Forums Version.

Chaos 2
Chaos 2 is the only boss map that works in this build.
 * All textures are missing.
 * Knuckles has a camera in this build (CAM1600K.BIN), as the game locks the camera on the boss, it's redundant, the file's blank, suggesting it had already been scrapped.
 * There's also another file present for Sonic (CAM1600S.BIN), which is interesting as Chaos 2 is a Knuckles exclusive boss fight, this camera file is also blank.

Chaos 4

 * There doesn't seem to be any differences with its geometry.

Chaos 6

 * There's two versions of the stage file, one (B_CHAOS6.PRS), is a PRS compressed file, but the other (LAND1800.BIN), is left uncompressed. The uncompressed version is three days older than the compressed version, and only has level geometry.
 * Knuckles' version of the fight (1801) doesn't have a level slot.
 * There's 2 blank camera files, CAM1800S.BIN and CAM1800K.BIN, this suggests Knuckles was originally going to be in Act 1.
 * The SET files are missing.

Perfect Chaos
The map for Perfect Chaos is entirely different compared to the final.
 * The map only has one stretch of path, the final version is loop shaped so the player doesn't have to go back and forth, the buildings are also much taller.
 * The textures for this stage, (LM_CHAOS7.PRS), are present, the final file used is much larger (LM_CHAOS7_0.PRS).
 * The textures don't actually match the geometry, this is because the list is wrong, decompressing the stage file shows a different texture list. Rearranging the texture archive to the stage file version will make the textures match the geometry.
 * The SET file (SET1900S.BIN) actually has some data in it.
 * The CAM file (CAM1900S.BIN) is missing.

Egg Hornet

 * Sonic has a camera in this build (CAMEGM1S.BIN), as the game locks the camera on the boss, it's redundant, the file is blank, suggesting it has already been scraped.
 * The map is a much older version of the Mystic Ruins map, it lacks any details or structures, just contains the (very) basic geometry.

Egg Walker

 * While missing from the disc, at D5E78 in 1ST_READ.BIN, there's a stage list which references EGGMOBILE2 (Egg Walker).

Egg Viper

 * The ID seems to have just been added in, as there's no geometry.
 * This is the only stage that doesn't have a camera file

E101 Beta (R)

 * While Mark 1 missing its ID, at D5E78 in 1ST_READ.BIN, there's a stage list which references E101 (E101 Mark 1).
 * Mark 2 does have a slot however.

E103 Delta

 * Goes unused due to Gamma not having a SET file in Windy Valley 1.
 * The title card just reads "E103".
 * Can not be harmed when gliding, as it won't come down after.

E104 Epsilon

 * E-104's boss fight is present in the game if the player manages to load up Gamma's Red Mountain and proceed through it.
 * E-104 does not experience any knockback or visual effects when hit.
 * E-104 also does not release an animal when defeated.
 * The boss music (Heartless Colleague) does not play during this fight.

Zero

 * The way the files are named is different (###ROBO#.BIN), in the final, it's (###ZERO#.BIN).


 * Sonic has a blank camera file for this boss, while Amy doesn't.
 * Sonic also has a SET file for this boss, and it actually has some data in it! It's dated August 8th, 1998. This makes it one of the oldest files in the build.

Chao Gardens
The Chao system is very limited in comparison to the Chao system used in the final. All Chao in the garden will stay completely still until the player approaches them, when they will then run up to the player continuously. If a Chao gets hurt by the player, they may decide to briefly run away from them instead.

System Differences

 * The Chao make "Chao Chao!" sounds constantly.
 * The sounds are unfinished, they sound more robotic than the final.
 * The animals don't affect the Chao's evolution in the same way as the final.
 * All the Chao in the garden are child chao.
 * Chao don't die from abusing them too much.
 * They're much more emotive in this build.
 * The animals will change a Chao's appearance instantly and more potently than the animals in the final.
 * The "evolutions" are actually the child Chao morphing beyond the limits that are in the final game, giving the appearance of a different Chao.
 * Chao do not recognise water and run around underwater as if they were on land.
 * Chao slide very far when thrown.
 * They can't age, this also makes them impossible to breed.
 * A very basic version of the garden camera is used. Pressing Y+L/R will zoom in and out unrestricted by characters, walls etc. In the final game, the camera only has 3 set zoom levels controlled by the D-Pad.
 * The baby Chao in this build start out walking. In the final, they crawl until their Run stat gets high enough to allow them to walk.
 * Coconuts don't fall from trees when shaken.

Station Square

 * This seems to be the same one seen in early screenshots.
 * The controls are disabled by default.
 * The player spawns one of each of the following animals: Rabbit, Deer, Kangaraoo, Elephant, Lion, Gorilla, Mole, Koala, and Penguin. Of note, the Flying type animals (Parrot, Swallow, Peacock) and two of the Swimming animals (Otter and Seal) are not spawned.
 * Eight Chao (the maximum number in a single garden in the final) spawn in set positions.
 * There's no tikal hints.
 * No garden warps, elevator or stadium entrance. It's possible to fall out of the map through the elevator's location.
 * The columns at the corners of the room are not solid.
 * The transporter says "NO DATA". Putting a Chao into it will cause the transporter to essentially "eat" the Chao - it won't ever come back out of the transporter and no VMU menu shows up.

Egg Carrier
The Chao Garden for the Egg Carrier is actually the same one used in early screenshots. It uses geometry ripped straight out of Windy Valley Act 3, with some details removed, it also references the same textures. It can't be loaded without hacking due to expecting a different version of 1ST_READ.BIN.
 * There's only one ring in the SET file.

Mystic Ruins

 * The Mystic Ruins Chao Garden has level geometry and not much else - it has no reference to textures whatsoever and only has rings in its object list.
 * There's only one ring in the SET file.
 * Can't be loaded due to expecting a different version of 1ST_READ.BIN.
 * Its geometry is an early model compared to the final (like with Casinopolis above) and has several differences:
 * The entire map is much smaller than the final.
 * The entrance is a rectangular cut out for a door instead of the tunnel-like minecart track exit of the final.
 * The entrance is to the left of the pool instead of to the right.
 * Because of the entrance's location, the raised portions of the layout present in the final are missing here.
 * There are no pillars or ruins present, unlike in the final.
 * The pool is a half-circle, like the cliff the level is built into cuts it off. In the final, it's a small full circle.

Chao Race

 * Instead of 2 CAM and SET files, only 1 is used.
 * The level geometry is similar to the final, though there are some differences.
 * The area where the races start has no hills surrounding it. There is also a large wall to the left that is not present in the final.
 * The third platform that the Chao get to in the Amethyst Course is floating. In the final, it is attached to the ground.
 * The bridge connecting the second and third platforms is an ordinary bridge. In the final, it is a bridge made of large blocks.
 * The arch over the path under the Amethyst Course's finish line is wider, and missing the water that flows through it in the final.
 * The island at the start of the Ruby Course is missing.
 * The end of the course has an arch over it that is not present in the final.


 * The Chao Stadium level is missing.
 * The CAM file is quite large.

Sky Chase

 * While listed as SHOOTING 1 and SHOOTING 2 on the level select, there's only one level slot.
 * Crashes due to expecting a different version of 1ST_READ.BIN.
 * There's a blank camera file named CAMSHTS.BIN in this build, though the final files are also included. This suggests that both acts used the same camera file at one point.
 * SETSHT1S.BIN and SETSHT2S.BIN are identical.
 * Only one enemy (HODAI), is included, the final version added two more types.
 * No path data exists.
 * The level has three texture files.
 * There's a 3rd object layout in this stage (SETSHTS.BIN), which references a bizzare number of objects. This includes:
 * The unused dragon.
 * Everyday furniture.
 * There's more furniture objects in this build.
 * The HUD is slightly different.
 * The dragon is completely different.

Twinkle Circuit

 * There's only one level model, and it's nothing like the final game. The geometry has small inclined areas that aren't seen anywhere in the final in any course.
 * The ID takes up the final's Past ID.
 * The object and camera files are blank.
 * The level lacks references to textures.
 * The SET file has data in it.
 * The CAM file is quite large.

Sand Hill

 * This build has a single camera file (CAMSBOARDS.BIN, with the S suffix for Sonic) for Sonic's minigame. In the final, two camera files are used instead.
 * This build also has a single set file (SETSBOARDS.BIN, with the S suffix for Sonic), which is smaller than its corresponding final. In the final game, there are two set files - one for Sonic, one for Tails.

Collision Display
Set 0x8C75AEB0 (0x2C for Demul) to enable a collision debugger, it shows active collision near the player, the display also lists information such as which side of an object the player is colliding with.
 * Colbuf is next to obj in this build, in the final, it's next to r-p.

Level Select
Like the initial Japanese and International releases, a level select exists. To access it, set 0x8C794C90 (0x2C instead of 0x8C for Demul) to 00 on the title screen to load the level select. Using the level select menu here will display the HUD properly in-game and allow you to control the character. The pause menu will not be enabled however.

To access the level select during cutscenes, demos, and gameplay, change the byte at 0x8C768B38 to 02. This method does not work on the title screen of this version, and will not give you control of the character unless you already had control (from loading a level from the title screen level select).

It looks as if the character select was meant to use icons here instead of names, but this doesn't function properly and just loads from whatever textures are in memory.

Hot Shelter is missing from this level select, along with Eggmobile 2 (Egg Walker), the Knuckles fight with Chaos 6 (listed separately in the final game's developer level select because of the changes to the arena in Knuckles's fight), the first battle with E-101, and "Eggmanrobo" (Zero).

SPR Task
The address 0x8C18EC94 activates a debug display with 3 displays showing various in-game information.

The AutoDemo version has an ADX feature which is removed from the final releases, It'll always appear at the bottom of the screen.

Title Screen


The title screen can be found in TITLE.PRS, it was replaced by a (also unused) beta version of the title.

Character Select
It's still possible the play the game similarly to how it was played at TGS.

There's a byte in RAM at 0x8C794C90 (0x2C instead of 0x8C for Demul) that controls what menu you're on, setting this to 03 on the title screen will make the screen fade to black before displaying the Character Select. Once a character is chosen, you'll get to play a single stage with 96 lives and 50 rings, though you can't pause the game.

Knuckles tutorial is also present, and it works perfectly.

English TGS Screens
Interestingly, English versions of the instructions exist. They were never used at TGS, nor the Autodemo, and were later deleted. They can be found in USA_SOUSA.

An english version of Knuckles' Tutorial also exists in K_TUTORIAL_USA, it was also later deleted.

Oddities

 * There's a blank camera file called CAM0B00S.BIN, if B is converted into decimal, it's reads 11, which is otherwise a skipped level ID in the final.

Research Credits

 * Sonic Retro (Info)
 * The Cutting Room Floor (Info)
 * AdvancedPlayer (Uncovering more info)
 * Its Easy Actually (Knuckles' unused combos, along with some other stuff)
 * PlayDifference (Demo video)
 * Main JP (TGS Menu Video)
 * SPEEPSHighway (Various Level Videos)
 * OrangeFox (Dumping the Autodemo)