Sonic Platform Game 1
A simple Sonic the Hedgehog platform game where you run to the end as fast as possible. It's just one level though.
Mighty The Armadillo
This is one of the earliest Sonic rom hacks ever, with a new character and a modified Green Hill Zone.
Sonic Advance 3
Dr. Eggman has created the wicked robot G-merl, and Sonic and Tails must intervene to stop him.
Sonic Triple Trouble MS
It is virtually the same game, but a hack of the original Game Gear version to accommodate a wider viewing area.
Sonic Trip
Sonic is trapped in an underground complex filled with enemies. Can you get him out alive?
Sonic 2 Retro Remix
This rom hack puts an emphasis on exploration and finishing tasks like collecting Chaos Emeralds or taking out bosses.