Proto:Sonic Adventure (Dreamcast)/AutoDemo



The AutoDemo is a build of Sonic Adventure designed to showcase the game through preset CPU-controlled demos of certain stages in the game. With a burn date of October 16, 1998, this build predates the Japanese final release by approximately two months.

Upon digging through the AutoDemo's contents, however, a plethora of unused and never-before-seen content was found to be inside...some of which was thought to be lost to time. It was recovered and released on May 21, 2013 by a user on the Sonic Retro forums.

Music
A surprisingly-large 29 tracks are present in the build, some of which have noticeable differences from the final tracks. Official track titles are named before the stage titles in this section.

28.adx (Title Screen)
Only a 5-second riff of Open Your Heart as opposed to 13 seconds.

Blue Azure World (Emerald Coast | Act 1)
A guitar is missing from the track, at least in the opening notes.

Run Through the Speed Highway (Speed Highway | Act 1)
This track plays at a slightly faster tempo than its finalized mix.

Goin' Down (Speed Highway | Act 2)
This track loops once in the AutoDemo as well as a longer fade-out, as opposed to playing once as its finalized mix.

Red Hot Skull (Red Mountain | Act 2)
The track plays longer. In fact, it nearly matches the length of its official soundtrack release!

Danger Chased by Rock (Lost World | Act 2)
Appears to be missing some instruments.

Theme of Chao (Chao Garden)
One of the tracks with the most noticeable changes, particularly in the drum beats which give the track a more mellow feeling.

Test Levels


Three rough test stages are present within the code. They appear to have been designed to test the engine and physics, among other elements.

Windy Valley


The geometry and level design for the fabled prototype version of Windy Valley seen in the game's official Japanese unveiling are partially intact. The proper textures are missing, however, and thus the model substitutes its textures for those of Red Mountain in the screenshots.

All three parts have their original texture listings and start positions present in the game's coding, although the level file itself only contains Parts 1 and 3, skipping the old tornado section. While the mesh for part 2 does exist, it doesn't have the necessary entries in the level file itself.

Level Select
Like in the initial Japanese release and the US release, a level select menu can be accessed. In this version change the byte at 0x8C768B38 to 02 during a cutscene or demo. This does not work on the title screen of this version, and it does not give you control of the character. 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.

Other Oddities

 * 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.