Amy Rose in Sonic the Hedgehog 2 (aka Amy in Sonic 2) is a character swap hack Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis, with character Amy Rose as playable character in place of Sonic the Hedgehog. The game's sprites (modified from Sonic CD) use Amy's initial design prior to Sonic Adventure.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.

Amy Rose in Sonic the Hedgehog 2 (aka Amy in Sonic 2) is a character swap hack Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis, with character Amy Rose as playable character in place of Sonic the Hedgehog. The game's sprites (modified from Sonic CD) use Amy's initial design prior to Sonic Adventure.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.

Chip McCallahan in Sonic the Hedgehog is a Sonic 1 hack created by MainMemory. It replaces Sonic the Hedgehog with Chip McCallahan, the main character inChip's Challenge. Chip can't run fast, roll or jump high, and rings do not protect him from damage. When you die, you will get one of the death messages from Chip's Challenge, and the level will restart with no decrease in your life count.

Chip McCallahan in Sonic the Hedgehog 2 is a Sonic 2 hack created by MainMemory. It replaces Sonic the Hedgehog and Tails with Chip McCallahan, the main character in Chip's Challenge. Chip can't run fast, roll or jump high, and rings do not protect him from damage. When you die, you will get one of the death messagesfrom Chip's Challenge, and the level will restart with no decrease in your life count.

Eggman the Dictator in Sonic the Hedgehog (aka Eggman in Sonic 1) is a rather interesting hack of Sonic the Hedgehog made by L0st - Sonic is replaced byEggman, who runs through the stages. Due to Eggman's larger sprites, the mappings and collision engine were rewritten from scratch, and Eggman also jumps at the same height and runs at the same speed, above and below water. As a result, Eggman cannot collect rings, open item boxes, destroy enemies, be hurt by objects or drown—the only way to kill Eggman is by landing on spikes, getting crushed, or falling off the screen (all three of which require a reset). Because of this, the hack is little more than a novelty, but is an impressive one nonetheless. Eggman can't use debug mode either, but Level Select still works. Also the Special Stages are unchanged, as Eggman can't enter Special Stages from the main game.

Kirby in Sonic the Hedgehog 2 is a hack of Sonic the Hedgehog 2 by Lone Devil (Also known as Darkon360) for the Sega Genesis/Megadrive. It features Kirby and Waddle Dee whom replaces Sonic and Tails as the lead protagonists. Kirby can inhale monitors and most enemies but cannot copy their abilities. Lives function as health points and the only way to obtain them is grabbing every 50+ Rings, Checkpoints/Lampposts, Randomized 1Up Monitors, or Score every 50000+ points. The hack also features 4 difficulty modes. Hidden Palace is restored but only as a 1 Act Zone for Kirby, located somewhere in Mystic Cave Act 2.

Knuckles in Sonic the Hedgehog is a fan-made ROM of the game Sonic the Hedgehog for the Sega Mega Drive/Genesis, featuring the character Knuckles the Echidna in place of Sonic the Hedgehog, the game's usual protagonist. The history of the game begins with the release of the Mega Drive game Sonic & Knuckles. The unique cartridge featured "Lock-On Technology" and allowed players that also owned the game Sonic the Hedgehog 2 to link the two together and play the game through as Knuckles instead of Sonic. However, partly because of a poorly matching colour palette, no such feature was included in the first Sonic game (instead, attaching Sonic 1 to the Sonic & Knuckles cartridge unlocked the full version of Blue Sphere). In the ROM hacking community, creating a patch that allowed the gamer to play as Knuckles in Sonic the Hedgehog was considered the "Holy Grail of ROM Hacking." On September 1, 2005, Stealth created a hack that allowed a player to do just that. His hack was called Knuckles the Echidna in Sonic the Hedgehog (Knuckles in Sonic 1, or S1K for short) Knuckles in Sonic 1 one gives Knuckles all the moves he has in Sonic and Knuckles, including gliding, wall climbing, and the spin dash. Not only that, Knuckles can transform into his Super form once he obtains all the emeralds (a cheat must first be enabled).