Sonic 2 Long Version (which is released alongside Sonic 2 & Knuckles Long Version) is a more complete version of Sonic 2, which makes it somewhat similar to Sonic 2 Delta. This hack features four levels originally scrapped during Sonic 2's development. No levels have been changed, only added. This hack was written in hex, without the aid of any special hacking programs, because the creator uses a Mac, and no hacking tools had been released on that platform at the time of development.

Sonic the Hedgehog 2: Pink Edition is a character swap hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis, with Amy Rose and Cream the Rabbit replacing Sonic the Hedgehog and Tails respectively. Amy Rose's sprites are designed after her modern look. Amy Rose with classic-style sprites is available to play in the Amy Rose in Sonic the Hedgehog 2 hack. The game was modified by Sonic Retro Member E-122-Psi, with additional programming and coding by other members including MarkeyJester, MainMemory, FraGag, Selbi, and Hayate. Most programming unique from Amy In Sonic 2 such as Cream the Rabbit's gameplay was implemented by Flamewing.

Sonic the Hedgehog Genesis (Genesis) is a hack of Sonic the Hedgehog by Xenowhirl which attempts to recreate certain aspects of the Game Boy Advance Sonic 1port titled Sonic the Hedgehog Genesis.

Sonic the Hedgehog Megamix (commonly shortened to Sonic Megamix) is a work-in-progress multiperson disassembly modification of the original Sonic the Hedgehog videogame for the Sega Mega Drive / Genesis, developed by Team Megamix and more recently moved to the Sega Mega-CD. The game features the ability to play as one of five different characters: Sonic the Hedgehog, Mighty the Armadillo, Shadow the Hedgehog, Miles "Tails" Prower, and Knuckles the Echidna. It is an extensive reworking of the original game, featuring new art, music, abilities, layouts, and other things.