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 2 XL is a hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by Captain Bozo and Ranger. Rings are replaced with onion rings, and Sonic becomes fatter after eating them.

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 3 Complete is a hack of Sonic 3 & Knuckles which aims to provide a much improved variant of the original game, with many new options and features, without straying from the original levels or gameplay. The inclusion of separate modes for Sonic 3, Sonic & Knuckles and Blue Sphere also make this a close cousin of the PC compilation Sonic & Knuckles Collection, albeit designed for the original 16-bit hardware.

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 Mega Blitz is a hack of Sonic the Hedgehog (16-bit) made by SSE. It is named "Sonic the Hedgehog Mega Blitz (Sonic Mega Blitz)" Due to the fact that the hack is a "blitzed out" version of the original game.

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.