Sonic the Hedgehog 2 (CENSOR prototype)

From Sonic Retro

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Sonic the Hedgehog 2 (CENSOR prototype)
Prerelease of: Sonic the Hedgehog 2
System: Sega Mega Drive
Build date: 1992-09-1X
ROM size: 1 MB
Source: EPROM cartridge
Found by: CENSOR, drx, Evilhamwizard

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

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.


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.


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.

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  • 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.

Hidden Palace Zone

Through rom hacking a save state, you can enter hidden palace zone and some zone ID levels too. Hidden palace is still a total mess but more stable then the final version still having enemy data.



Download Sonic the Hedgehog 2 (CENSOR prototype)
Multiple downloads available

External links


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

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

Sonic the Hedgehog 2 (16-bit)
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Main page (KiS2|2013|3D|Ages)
Comparisons (KiS2) (2013)
Maps (KiS2) (2013)

Promotional material
Magazine articles
Video coverage

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