Sonic the Hedgehog 2 (CENSOR prototype)

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S2b4 titlescreen.png
Sonic the Hedgehog 2
Publisher: Sega
System(s): Sega Mega Drive
ROM size: 1 MB
Genre: Action

The Sonic the Hedgehog 2 "CENSOR" prototype is a prototype build of Sonic the Hedgehog 2 for the Sega Mega Drive.

This build was originally released on November 9th, 1992 by an old ROM dumping group known as CENSOR, just a few weeks before the game's final release, only to be forgotten in favor of a dump of the final game by a group called MAGICAL. Partially due to people not wanting a prerelease version of Sonic 2 at the time (yes really). [1] It wasn't until February 14th, 2019 that drx and Evilhamwizard discovered the prototype in old scene releases and released the prototype on Hidden Palace.

The prototype itself is very similar to the first of the numerous internal testing prototypes from the Sega QA Archive. However, there are a number of differences in this build that place it before "beta 4", and could potentially be the missing "beta 3". Most of the differences in the build compared to "beta 4" are mainly found in Chemical Plant Zone and Wing Fortress Zone.

The original ROM was modified to include a scene intro and to bypass the copy protection. The header was also modified in an effort make the title easier to see when selecting the game from a copier, and the serial number was altered to the one from Wani Wani World. A modification of the ROM was also released on Hidden Palace that removes the intro and restores the ROM back to the way it was meant to be.

The original build date is unknown due to it being hacked, but because of how similar it is to Beta 4, it was likely built sometime in September.


Sonic Retro emblem.svg Main article: Sonic the Hedgehog 2 (CENSOR prototype)/Comparisons

Cheat codes

The Level select and debug mode are both enabled by default in this prototype. Simply press A + Start when selecting "1 PLAYER" on the title screen to access the level select, then hold A when selecting a Zone to activate debug mode. However, like in "beta 4", debug mode is limited in that accessing edit mode is not possible.

Differences from Beta 4

  • Collision is different to later prototypes.
  • Hidden Palace still has some leftover collision data which was deleted in Beta 4.
  • Sky Chase has more rings present.
  • Special Stages take a long time to load, this is because the art is compressed in separate archives. This was fixed in Beta 4 by having most art compressed together in a single archive.
  • Wing Fortress is slightly different.
  • This is the last build to have Chemical Plant's loops slanted as opposed to fully square.



Download Sonic the Hedgehog 2 (CENSOR prototype)
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External links


Sonic the Hedgehog 2 (CENSOR prototype), prerelease version of Sonic the Hedgehog 2 (16-bit)
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Main page | Comparisons | Level maps

Part of Sonic the Hedgehog 2 (16-bit) development

Sonic the Hedgehog 2 (16-bit)
Sonic2 title.png

Main page (KiS2|2013|3D|Ages)
Maps (KiS2)
Comparisons (KiS2)

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Hidden content (KiS2) (2013)
Bugs (KiS2)
Region coding
Hacking guide