Proto:Sonic the Hedgehog 2 (Genesis)/Simon Wai Prototype

The Simon Wai prototype of Sonic the Hedgehog 2 is definitely further along than the Nick Arcade prototype, but there are still quite a few unfinished elements such as level layouts and things that have not been fully implemented. There are also many, many unused graphics that can be found via hacking. In addition, there are a few levels not seen in the final, but most of them contain nothing.

The prototype is named after Simon Wai, who found it on a Chinese Geocities page in 1998. The actual ROM image likely came from a demonstration cart that was stolen from a New York toy fair in 1992, then dumped.

General Notes

 * At this point, Tails is still interdependent. That is, the second player is able to control Tails, except Tails will also follow Sonic. Also, Tails cannot complete a level on his own, since the game only loads the goal sign when Sonic approaches it. The AI is much simpler; it only follows Sonic and does not try to keep up. Tails loses the player's rings when he is hit. If he dies, he drops back in from the top of the screen and immediately goes into a roll when he hits the ground because he can't fly yet.
 * If player one completes a level, Tails can be controlled if Sonic is off-screen.
 * As with the Nick Arcade build, the spin dash is still a work-in-progress, as Sonic and Tails can only charge it up once; the sound for when Sonic spins in Sonic the Hedgehog is still heard due to there not yet being a specific sound effect for the spin dash.
 * Any zone with water will be glitched when playing in two-player mode, as the game loads the graphics incorrectly.
 * The underwater countdown music uses the level select theme. When Sonic gets out of the water, the Emerald Hill music begins.
 * Special Stages are still not present, although the music is.
 * A unique bug is present in this prototype. Upon collecting 100 rings, the game will play the Death Egg Zone music instead of the usual 1-up sound. This is because sound bank 88 (which was the 1-up sound in the Nick Arcade build) has since been overwritten and not edited to play the correct sound. The monitors, on the other hand, were programmed with the correct 1-up sound.
 * The only levels that can be accessed without the level select cheat code are Aquatic Ruin Zone, Chemical Plant Zone, Hill Top Zone, and Emerald Hill Zone.
 * Bubbles are loaded incorrectly from the VRAM.
 * The SEGA logo does not appear when booting up the game, likely because the ROM file was slightly altered by pirates.
 * Locking on this prototype with Sonic & Knuckles will unlock the full Blue Sphere game, as it does with the Nick Arcade build.
 * As with the Nick Arcade build, the timer resets to 9:00 when it approaches 9:59 in order to allow the player to test the stages for extended periods of time.
 * The screen doesn't scroll up or down when you look up or down for a certain period of time.

Cheat Codes

 * Level Select - A + Start.
 * "Night Mode" - C + Start.
 * Two-Player Mode - on the level select, press B + Start on any level.
 * Debug Mode - C, C, Up, Down, Down, Down, Down, Up. You can also enable it through the patch code.

Zones
Without accessing the level select, the game allows you to play Aquatic Ruin, Chemical Plant, Hill Top, and Emerald Hill. After beating the Emerald Hill boss, the game resets to the Sonic 1 SEGA screen despite being disabled from appearing at startup.

Neo Green Hill Zone (Aquatic Ruin)

 * The underwater portion is not yet implemented, so you will die if you miss the swinging platform in Act 2.
 * The only enemies present are the arrow-shooting Robotnik-face totems.
 * The splashing animation is corrupted, showing misaligned bubbles instead of a splashing sprite. Tails has no splashing effects.

Chemical Plant Zone

 * The loops have slanted corners instead of 90-degree corners, as in the Nick Arcade build.
 * The platforms which move across rails are much smaller.
 * The blue bubbles that jump between tubes make a different sound effect.
 * Demo gameplay is the same as the Nick Arcade build, and has not yet been rerecorded to fit subsequent layout changes.

Hill Top Zone

 * Sonic doesn't spin when going through tunnels.
 * Earthquakes are silent.
 * Act 2 ends a bit early.
 * Demo gameplay is the same as the Nick Arcade build, and has not yet been rerecorded to fit subsequent layout changes.

Green Hill Zone (Emerald Hill)

 * A snail-type badnik appears here, like in the previous build.
 * Demo gameplay for 2P Mode is the same as the Nick Arcade build, and has not yet been rerecorded to fit subsequent layout changes.
 * At one point, there is a hidden wall which is supposed to contain an extra life; it does but it is blocked off. The only way in is by staying on the falling platform.
 * This zone and Hidden Palace are the only zones in this prototype with badniks in it.
 * As with the previous build, this zone contains the only boss you can fight. However, the machine does not explode when destroyed, even though the Sonic 1 explosion graphics are still present in the ROM.

Oil Ocean Zone

 * The music is what would eventually become the final's 2P VS version of Casino Night, even though the normal Oil Ocean theme is present in the sound test.
 * Act 1 is playable to the end of the level, where there is no signpost. However, many objects present in the final are missing, making it much harder to play through.
 * Act 2 cannot be played more than a few seconds in without debug or glitching, and the level layout is very different from the final.
 * The palette cycle is reversed, making it look like the sewers are sucking up the oil.
 * The sun also does not animate nor scroll.
 * The oil splashing animation is missing and oil slides have no effect on Sonic.
 * A mechanic is present which features a rolling checkered ball (like the scrapped ball in Sonic 1) that springs up and rolls along when a button is pressed. While cut from the final, it can be placed in debug.

Metropolis Zone

 * The stage background uses an orange palette instead of a blue-gray one.
 * The pistons take longer to pop out of the ground, and they don't launch Sonic very high.
 * The metal crushers can only crush Sonic if he is at the bottom. If he is at the top, he will simply be shoved upward.
 * Some rotating nets work, while others don't.
 * The corkscrews will also not stop turning, meaning the player can potentially go as high as he/she wants.
 * Neither fire or lava can harm the player.
 * A parallelogram-shaped machine that moves horizontally and diagonally through narrow corridors appears in Act 3.
 * You cannot complete any of the acts.

Dust Hill Zone (Mystic Cave)

 * Both acts use the level layouts present in the final game, but have few or no objects, and no rings.
 * It seems Act 1 was only used for object testing, as the first half has a bunch of randomly placed objects and the other half is empty.
 * The bridge object works in Act 1, but uses a switch to open instead of vines seen in later builds.
 * Act 2 is completely devoid of objects.
 * There is no signpost/boss/capsule in either act, making them both unable to be completed.
 * The name of this Zone is misleading, and most likely left over from an older build of the game.

Casino Night Zone

 * The level looks completely different, with a pink card-suit-based scheme and sky blue floors.
 * Act 2 has a screwed-up background, since it is accidentally overwritten with the pinball table graphics.
 * There are no objects or enemies, and debug mode only has the default Ring / Static Monitor.
 * Many of the flipping tiles are missing or the outlines flash and the tiles remain stationary. With hacking, it is possible to implement the rotating tile, albeit without its flipping format.
 * There are no Sonic, Miles, or Casino tiles. Instead, these are part of the layout tiles themselves.
 * There are many solid black areas in the zone tiles that should be transparent.
 * There is a different sound for the bouncers that give points and disappear after three hits (and don't yet exist).
 * Tile layout is pretty similar to the final, but many level pieces are broken or missing; as such, the level is impossible to play without debug.
 * The red bumpers that give 10 points per hit do not exist. If the object (obj44) is placed in the level, it instead places a solid wall similar to the one from Green Hill Zone. This is a leftover from the Nick Arcade Prototype.

Wood Zone

 * It seems that only a small portion was ever implemented and did not get too far. What exists of the level quickly ends because of a ramp that has a platform blocking the top of it, which is impossible to get past without debug.
 * If you use debug, you can move upwards in the level and find a conveyor belt, but it doesn't work.
 * Level collision is glitchy.
 * A background is present, but doesn't seem to be complete.
 * Act 2 is empty, containing nothing but Sonic and Tails falling to their deaths.

Hidden Palace Zone

 * This zone has had mainly minor behind the scenes changes in it since the Nick Arcade build.
 * Sonic and Tails have had their underwater palette updated.
 * The music has been changed to what would be the 2P VS version of Mystic Cave in the final.
 * The Debug list has had a face lift, and all the unused objects that were in the Nick Arcade build are now gone. The items that are still there have fixed previews.
 * The collision bug caused by spindashing into the big emerald from far away has been fixed.
 * The art for Emerald Hill Zone's enemies is no longer loaded in this zone.
 * This and Emerald Hill are the only zones in this build with badniks in it.

Genocide City Zone

 * Both acts use Chemical Plant's music, Emerald Hill's palette, and the default Ring / Static Monitor objects in debug mode. They're also completely empty.

This zone was originally designed as a single-act mechanical-themed area. It is called "Genocide City" in this prototype because of an average understanding of English by the person who originally named it, then changed to Cyber City after this prototype. Before the team started putting it in the game, it was scrapped; the level design was used for Metropolis Act 3, while the graphics were used in Level 3 of Sonic Spinball (The Machine).

Death Egg Zone

 * Both acts use Emerald Hill's palette, but play no music and are empty. Dying here causes all sound to cut off.

Music
The tracks for the final's invincibility, drowning, ending, and credits themes are all nonexistent while the continue, game over, extra life, and Chaos Emerald fanfares are already in their final form. Everything else, however, is at least slightly different.

Title Screen
The first kick before the opening snare is missing, as well as the last snare sample before the main melody begins. A snare roll and several fills are gone. The bass is much heavier, and there is no "twinkle" at the end.

Stage Select
The snare sample has been replaced with a kick, and the trumpet sample is heavier. A backing trumpet in the left channel is instead a celesta. The right channel has an extra bottle-like instrument.

Neo Green Hill Zone (Aquatic Ruin Zone)
The instrumentation is heavier and lacks a backing part in the left channel.

Chemical Plant Zone/Genocide City Zone
About 1.4% slower than the final, and the first pitch bend before the loop comes in late.

Hill Top Zone
About 11.35% slower.

Green Hill Zone (Emerald Hill Zone)
About .3% slower, and some of the percussion is more distinct.

Wood Zone/Metropolis Zone
About 1.6% faster. The instrumentation is radically different, with more grating and off-key tones. Also uses a different off-beat sample, and the melody has a simpler, downward pitch bend.

Hidden Palace Zone (Mystic Cave 2-Player)
About .6% faster. The intro has more quavery instruments, and the mix is overall less full.

Oil Ocean Zone (Casino Night 2-Player)
About 10.75% slower.

Unused (Oil Ocean Zone)
About 8.35% slower. Has more distinctive intro instrumentation, and some backing instrument samples are slightly different.

Dust Hill Zone (Mystic Cave Zone)
About 6.6% slower.

Casino Night Zone
About 12.93% slower. The instrumentation is much different, giving a sleazier feel. The percussion and bass are much more ornamented. The prototype has an extra harmony line just before the loop.

Unused (Sky Chase Zone)
About 6.95% slower, and has a louder bell sample.

Unused (Wing Fortress Zone)
About 6.23% slower. The backing instruments are slightly altered and much louder, sometimes to the point of almost drowning out the melody.

"100 Rings" Extra Life (Death Egg Zone)
About 15.65% faster, and has much fainter and sicklier instrumentation. The percussion is also very different.

Act Complete
Seems to have a very slight jump in the first two notes that the final doesn't.

Dr. Robotnik
About .25% slower. Has a much heavier mix, and a faint additional backing part.

Unused (Final Boss)
About 1% slower. Has a different, less distinct kick sample.

Invincibility (Super Sonic)
About 7.4% slower. The right channel has an extra "alarm" instrument in the intro. This was later replaced with a different theme and became the music for Super Sonic.

Unused (2-Player Results)
About 1.5% slower.

Unused (Emerald Hill Zone 2-Player)
About 6.64% slower. Has a slightly shorter kick sample.

Unused (Special Stage)
Has a very slightly more prominent kick sample.