Sonic UMZ is a hack based on Sonic 2 made by Trinitronity Special Thanks given to:MainMemory: SonLVLEzrael: Bugfix on how to make Sonic retain his rings at a checkpoint only after exiting a special stage.

Sonic Frenzy is a hack based on Sonic 2 it mainly features modified art and level layout in an attempt to create a fresh classic sonic experience. Currently contains two new zones with unique layout and multiple and varied level routes.The hack made by SteamPoweredPixel

Sonic the Hedgehog 2Z is a palette and level layout hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by Mystic. The objective is to make a harder version of Sonic 2 for experts who really haven't had a challenge in Sonic for years. In order to do this, Mystic made some exceedingly challenging levels, which are definitely going to make even a master Sonic player beg for mercy in a few sections.

Sonic The Hedgehog ZX (also known as Sonic 1 ZX or S1HZX for short) is a hack made by CarrascoZX0 and his team, Team ZX. This hack features the ability to play as Sonic the Hedgehog or Knuckles the Echidna. The hack also features new art, abilities, level layouts, music and much more!

Sonic Zeta Overdrive is a hack of Sonic the Hedgehog 2 for the Sega Mega Drive by Mikel. Plans as of now include adding the Centisecond timer.

Sonic: South Island Warped is a currently in progress hack of Sonic the Hedgehog. It's main point of interest is the return of the time travel mechanic from Sonic CD, along with a few other new features added to set it apart from the original Sonic 1. Zones are split into four acts each; three main acts and and a boss act at the end. Sonic is capable of traveling to the past or the future of the zone he's currently in via the signposts hidden in each of the levels. Each act, sans act four, has a robot generator that, when destroyed in the past, will remove all badniks for the rest of the act and also create a good future for that act. Destroying all three generators for a zone will remove Eggman's influence in the fourth act, which always takes place in the future.Time Stones also return, collectible alongside the Chaos Emeralds. One Time Stone will be hidden in each zone, and it will only be obtainable within the future of that zone. If attempting to retrieve the Time Stone in the bad future, Sonic will have to face off with one of Eggman's machines. If in the good future, the Time Stone will be unguarded and ready to be collected. The fourth act of a zone contains no generators, Time Stones, or signposts, only a boss fight against either Eggman or Metal Sonic. The Chaos Emeralds will be obtained during these boss fights, usually right after the boss is defeated, but you may also be able to reach it before the boss does, preventing it from making the fight more difficult.As of now, this is just a demo of GHZ, which even on it's own is still in need of much work. Honestly there's a lot I couldn't get around to doing just yet, but I still wanted to give everyone a sample of what I'm making. More than anything, I just hope you all enjoy what you play. Everything in this is release was done by me with the exception of the sound driver and the one original song port done for this hack. Both of those were by Varion Icaria who I can't thank enough for helping out. Also have to give a thanks to the many users of both Sonic Retro and SSRG who made all of the informative guides and tutorials hosted on both sites.