Metal Sonic in Sonic 3 & Knuckles is a hack of Sonic the Hedgehog 3 & Knuckles. It was created by Darkon360/GothicReaper/LoneDevil. Metal Sonic is playable, complete with additional special moves.

Metal Sonic in Sonic the Hedgehog is a hack of Sonic the Hedgehog created by Darkon360/GothicReaper/LoneDevil. It stars Metal Sonic as the playable character instead of Sonic the Hedgehog. The game is modified to use Metal Sonic's sprites in place of Sonic's. The hack comes with 4 different play styles: The Original, Sonic 2Spindash, Sonic CD, and Sonic CD 2011.

Metal Sonic Rebooted is a complete heavy modification of Sonic the Hedgehog 2 by Lone Devil for the Sega Genesis. it features an extensive amount of new art, layouts, mechanics, music, and features that in total creates a different experience.StoryDr'Robotnik has built an advanced army of badniks to search for the Chaos Emeralds, and it's up to Metal Sonic to find the emeralds before them by destroying everything in his way to show Robotnik he shouldn't be replaced.CreditsKCEXE - Music and SFX ports from various Genesis/Megadrive gamesEduardo Knuckles - Music for Magma FactoryClownacy - Sonic 2 Clone Driver v2Dark Sonic - Hardware Testing for v1.1

Metal the Hedgehog is a hack of Sonic the Hedgehog where Sonic and Tails are replaced by Metal Sonic and Charmy Bee. Made by Kampfer.

Mighty the Armadillo in Sonic the Hedgehog (aka Mighty in Sonic 1) is a hack of Sonic 1 by E-122-Psi, starring Mighty as the playable character instead of Sonic the Hedgehog. The game is modified to use Mighty's sprites in place of Sonic's, along with several modifications to the player's stats and abilities.

Mortal Kombat II Unlimited is a full scale hack of the Sega Genesis Mortal Kombat II game, Originally work on the hack ceased with version 07, but in 2011 version 1.0 was released which added many new graphical features. Added a combo system;Secret fighters now fully playable;Bosses now fully playable;More new sounds;New Select Screen and Main Menu;New stages and music from Mortal Kombat 1;New moves such as Brutality;New Game Modes such as Practice and Endurance;Returned biographies/Endings/Intro/VS-screens from the arcade version;and many more…

Motobug the Badnik in Sonic the Hedgehog (aka Motobug in Sonic 1) is a hack of Sonic the Hedgehog for the Sega Mega Drive, by Polygon Jim. As its title suggests, in this hack the main character Sonic the Hedgehog is replaced by Motobug, one of Dr. Robotnik's badniks.So far, some of Sonic's main sprites and animations have been replaced by those of Motobug, Motobug's speed has been decreased (except when powered-up by aSpeed Shoes monitor, which are more numerous), and the sprites of Roller badniks in Spring Yard Zone have been replaced by those of Sonic (referencing a common interpretation by fans that Roller is a robotic impersonation of Sonic, something that officially appeared in later games in the form of Metal Sonic and various others).Of the first release, Polygon Jim stated that he had only tested and confirmed Green Hill Zone (Acts 1-3) for completability. However, upon testing, Katelynn andRGamer2009 reported that other Acts are completable, including:Marble Zone Act 1Spring Yard Zone Acts 1 and 2Labyrinth Zone Acts 1 and 2Star Light Zone Acts 2 and 3Final Zone