Sonic 2 Armageddon Game is a hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by xenoSonic. The layouts of the first four zones of the game have been altered, with the rest of the original levels unaltered. Additional levels are planned, but as yet are not implemented.

Sonic 2 Build A Burger is a hack based on Sonic 2 that captures the spirit of customization to a full "T". Thanks to the revolutionary menu system created my Vladikcomper, this hack now takes your experience of Sonic the Hedgehog 2 and multiplies it ten fold. Nearly every kind of option for your custom Sonic 2 has been considered and placed in the easy to use menu system. Because of this, each person can now create a custom Sonic 2 game at the touch of a button without ever having to mess with an external website, download links, or whatever else.

Sonic 2 Delta is a groundbreaking series of ROM hacks by famed Sonic scene member Esrael Neto, which restores several deleted levels and prototype elements to Sonic the Hedgehog 2 for the Sega Mega Drive / Genesis. Various features of Sonic 2 Delta, common across the series despite the existence of several versions/branches of the hack, include the use of art and music from the betas and Sonic the Hedgehog and re-implementation of badniks that had been removed from the final game. The level order of Sonic 2 Delta is also similar to the original intended order, rather than that used in the final version. The main version of this hack is entitled Sonic 2 Delta and was based upon the Simon Wai prototype, before version 0.24 transferred the codebase to 'revision 2' of Sonic 2 from Sonic Compilation. More information on the various lineages and their history is detailed in the section "Other versions" below. A hack similar in concept, called Sonic 2 Long Version, has been released by another hacker, Sonic Hachelle-Bee.

Sonic 2 Delta is a groundbreaking series of ROM hacks by famed Sonic scene member Esrael Neto, which restores several deleted levels and prototype elements to Sonic the Hedgehog 2 for the Sega Mega Drive / Genesis. Various features of Sonic 2 Delta, common across the series despite the existence of several versions/branches of the hack, include the use of art and music from the betas and Sonic the Hedgehog and re-implementation of badniks that had been removed from the final game. The level order of Sonic 2 Delta is also similar to the original intended order, rather than that used in the final version. The main version of this hack is entitled Sonic 2 Delta and was based upon the Simon Wai prototype, before version 0.24 transferred the codebase to 'revision 2' of Sonic 2 from Sonic Compilation. More information on the various lineages and their history is detailed in the section "Other versions" below. A hack similar in concept, called Sonic 2 Long Version, has been released by another hacker, Sonic Hachelle-Bee.

Sonic 2 Dimps Edition is a hack of Sonic the Hedgehog 2 by Spanner. This hack attempts to mimic what Sonic 2 may have been like if it were created by Dimps. This means incorporating many features found in Dimps games such as random speed boosters. This does not include features common in most modern Sonic titles with the exception of a homing attack. The hack was discontinued due to various reasons and there was currently no intention to return to it, except that somebody else now has the source code and is intending to finish off the job. Version 1.5 was uploaded to fix some reported bugs.

Sonic 2 EX (often abbreviated as S.EX) is a hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by Mr. EX. Its highlights include spring-based layouts like those of Project Shadow 2, new art and layouts, and original music.

Sonic 2 Megamix is the first installment in the Megamix series of hacks by Team Megamix, followed by Sonic Megamix. It was created by Tweaker for submission in the 4th Hacking Contest. It features edited palettes and music.Future plans were to revamp the hack, including moving it to a split disassembly and revamping the level layouts; the former of which has already been completed. It was also to contain various pieces of original music, as well as imports from other games, such as Sonic Advance 2, or Sonic Jam.

Sonic 2 Millennium Edition is a palette and layout hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by Striker.