Sonic 2 Retro Remix is a large-scale ROM hack of Sonic the Hedgehog 2 for the Sega Genesis / Mega Drive, created by Thorn and DNXDelta. The goal of the project is to create a 2D Sonic the Hedgehog game that requires exploration to progress, as well as the requisite platforming and sheer speed. A mission system akin to those of the 3D Super Mario games is implemented as the means of progressing from one level to the next. Missions involve earning Chaos Emeralds in scavenger hunts, boss battles, speed runs and score attacks; most require learning each level's ins and outs, instead of just finding the easiest way to the goal.

Sonic 2 Secret Rings Edition is a hack of Sonic 2 by MainMemory. It features no new art or level layouts, and few new features, instead adding replayability to the original game by adding various missions that you can attempt to complete, although there are several levels where completing certain missions is impossible, and some levels where it is impossible to lose.

This is a hack based if the original Sonic 2, that has been in the works for quite some time. It includes 4 characters to choose from all with different moves that fit them. Every level in this demo has had a background change, along with new music in each act. Layout changes (Knuckles has some of his own) and much more...Story: Shadow is back and teams up with Robotnik...Credits:Project Leader: JoenickROSLayout: NeofusionBox, JoenickROS, Markeyjester, Electroball, Shockwave, BakayoteMusic and Sound: JoenickROS, Bakayote, KCEXESounddriver: Flamewings S3K driverArt: Blazer, Bakayote, KCEXE, AsuharamoonMinor Coding: JoenickROSMajor Coding: Shockwave, Varion Icaria, RalakimusBeta Testers: Mike B Berry, ThomasSpeedrunner, Bakayote, Shockwave, Varion Icaria, NeofusionBox, King of HeartsNatsumi: Credits SequenceSpecial Thanks: Shockwave, and Varion Icaria, without them, I might have not been able to fix some of the coding bugs.