Mighty the Armadillo in Sonic the Hedgehog2011

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.

This is a hack which changes Sonic the Hedgehog for Genesis into a entirely different game with new gameplay. It stars Dr. Robotnik whom must capture creatures with a net and put them in creature capsules. The graphics are the same as previous Sonic games but the rest is mostly changed. Most levels are open by default.

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

Sonic 2: Pink Edition is a modification of Sonic 2 that replaces Sonic & Tails with Amy and Cream as playable characters, Amy's sprite being based off her modern design. The changes aren't just to the asthetics though, Amy and cream bring their own movesets to the table! Amy bringing her trusty Piko Piko Hammer to swing,jump,whirl and dash through Robotnik's obstacles. Cream bringing the spindash and ability to fly, oh! don't forget about her trusty Chao, Cheese who can attack enemies, even bosses, from a distance!

Metal Sonic in Sonic the Hedgehog 2 swaps Sonic out for Metal Sonic from Sonic CD, you can choose between the Original moveset, Sonic CD, or the 2011 remaster moveset from Christian Whitehead's port of Sonic CD Metal will once show Robotnik he's not a bot to be forgotten...

Amy in Sonic 1 is a modification of Sonic 1 that swaps sonic out with Amy Rose from Sonic CD, bringing with her, her move-set from Sonic Advance. Using Her Piko Piko Hammer she will have to Jump, whirl, and dash through South Island to put a Stop to Robotnik's plans.

Amy Rose in Sonic the Hedgehog 2 swaps Sonic out for Amy Rose from Sonic CD, equipped with her Sonic Advance moveset. She will have to Jump whirl and Dash through Westside Island with the help of her newfound friend Tails! Infiltrate the Death Egg and put a stop to the deadly Space Station using your hammer!

Shadow the Hedgehog in Sonic the Hedgehog brings the Ultimate Lifeform to South Island to put a stop to Dr. Robotnik's Evil Plans! He must skate across 7 perilous zones to free the animals he's trapped in his robots and collect the 6 Chaos Emeralds! Shadow's journey however isn't the same as that blue rodent, as he has the ability to use rings to fuel his rocket shoes for a boost! However the shoes use 5 Rings per boost so use them wisely! Shadow also brings the Light Speed Dash to the table working just like how it did back when he was the talk of the town! Simply hit A near a trail of rings to dash through them at light speed! Oh and did I mention that thanks to Shadow practicing his Chaos Abilities so much, he no longer needs the 7th emerald to go Super?