S2B/Sonic 2 Prototype Summary

Facts regarding this prototype has been compiled into this document. Significant bits are in bold. This is not meant to be a complete list of differences between prototype and final version. Insignificant details or way-too-obvious discrepancies are not included.

General

• Sonic 2 was built based on Sonic 1. Therefore many Sonic 1 elements were carried over to this prototype.
• This is a very early version of prototype. It's more of an "alpha" than "beta".
• The prototype ROM has been tempered with by pirates, who have removed the Sega and Sonic Team credit at startup.
• Sonic 1's "Sega" logo and voice is played after a demo or game is over.
• Holding up or down keys for a while will not temporarily make Sonic look up or down.
• Getting 100 rings plays Death Egg music.
• Canceling out-of-breath countdown plays Emerald Hill music.
• Invincibility plays Super Sonic music.
• Super Sneakers, while still does the job, only speeds up the zone music a little bit.
• Tails can destroy monitors, with the effects applied to Sonic.
• Tails loses rings on Sonic's behalf.
• Tails does not actively seek for Sonic but merely copies Sonic's moves with a constant delay.
• When Sonic and Tails are attacked at the exact same time, massive loads of rings come out.
• Tails cannot fly.
• Tails uses Sonic's icon in 2P mode.
• Tails does not walk up to Sonic when a level begins.
• Spindash charge-up sound effect is the same as normal spinning.
• Spindash release has no sound effect.
• Objects placed are vertically flipped if Sonic is upside-down before entering debug mode.
• Restart points can be placed using debug in certain zones.
• Some zones' music are playable in level select screen, even though their names don't show up in the level list.
• There is a prototype screenshot right in the Sonic 2 manual.

Chemical Plant Zone

• Corners of loops are shaped differently.
• An earlier prototype has different layout.
• A background building is different in an alpha prototype.
• An unused animation of Robotnik getting splattered by blue chemical is found within the prototype ROM through hacking.

Green Hill/Emerald Hill Zone

• When fighting the boss, Sonic's graphics are messed up if he has invincibility or shield.
• Boss flies straight down, instead of coming from the right as in final version.
• Boss has no helicopter sound effect.
• You can place a lost sprite, the high-tech star post, in this zone through debug.
• An earlier prototype has different layout.

Hidden Palace Zone

• The big green emerald ("Master Emerald") is only a breakable object blocking the tubes.
• Tails 1-up monitor does give Sonic an extra life, whereas the one in final version doesn't.
• Emerald Hill music is played after breathe counter is cancelled.
• A magazine screenshot of Sonic running off the ramp is a mock-up.
• An earlier, playable, version might be using different background.
• The trycerobot enemy is found within the prototype ROM through hacking.
• The final Hidden Palace Zone is the same as our prototype, with auto-spin at tube entrances.

<Unnamed Desert> Zone

• No credible evidence to support this level is called Dust Hill Zone.
• The only screenshot released from Sega featuring a desert level turned out to be a mock-up.
• The crocobot enemy is found within the prototype ROM through hacking. It may, or may not, be intended for this level.
• Little of this level was ever made. Presumably scraped before a playable version was created.

Dust Hill Zone/Mystic Cave Zone

Hill Top Zone

• Sonic doesn't spin when going through tunnels.
• There is no earthquake sound effect.

Neo Green Hill/Aquatic Ruin Zone

• Water level is shallow.
• Sonic's water-splashing animation is messed up.
• Tails triggers no water-splashing animation.

Metropolis Zone

• Pistons don't throw you very high up.
• Metal crushers and fire cannot hurt Sonic.
• Sonic falls through most of the rotating nets, but one of them does work.
• Sonic can rotate a nut upwards pass the height of the supporting screw pole.
• Act 3 has a special lift that was cut from the final game.

Oil Ocean Zone

• The sun scrolls with the background, and is non-animated.
• Wooden balls did appear in Sonic 1 prototype.
• Two seahorse enemies are found within the prototype ROM through hacking.
• An unused, shoot-and-flee octopus enemy is found within the prototype ROM through hacking.

Wing Fortress Zone

• Known as Sky Fortress Zone at one point during development.
• Music is present in our prototype.

Genocide City Zone

• Level is empty. Presumably canned at the very early stage of development.
• Apparently, no screenshot of this zone, mock-up or otherwise, was ever published.
• There's a slight graphical glitch involving a purple object in 2P.

Wood Zone

• Yes, we know the upper part of the level features conveyor belts, a series of small platforms, and flowery railings.