Sonic 1: Bouncy Edition is a physics hack of Sonic the Hedgehog for the Sega Mega Drive/Genesis by Xenowhirl. Based on the gameplay of Within a Deep Forest, the hack has modified Sonic's actions so that he is constantly bouncing. Other additional features include a snap screen, new special stage controls and the ability to use GHZ bridges as trampolines.

Few months after defeating Eggman in Metallic Madness, Sonic decided that he will return to South Island and see if everything is okay. Sadly, Eggman also returned and he wanted to get control over the island once again. Seeing that blue hedgehog is close to the island decided to burn it and hide in Scrap Brain, his old base. Now Sonic must defeat Eggman and get Chaos Emeralds again to restore the island old state before it's too late!The hack made by Team Painto

Sonic 2 but keep Tails or else is a hack by GT Koopa where you should keep Tails from respawning or else you will recieve a Game Over

Sonic 2D Blast Is a work in progress hack by Painto Maniak initially started as a proof of concept but with the amount of feed back recieved about the hack, he decided to continue it.

Sonic 3D Blast, known as Sonic 3D: Flickies' Island (ソニック３Ｄ フリッキーアイランド, Sonikku Surīdī Furikkī Airando?) in Japan and Europe, is an isometric platform game and the second 3D game in the Sonic the Hedgehog series, after Sonic the Fighters. It was developed in the United Kingdom by Traveller's Tales and published by Sega. Primarily developed as the last Sonic game for the Sega Genesis, it was later ported to the Sega Saturn and Microsoft Windows, and later re-released on many compilations and digital distribution platforms as well.A separate game, titled Sonic Blast, was also released for the Sega Game Gear in the same year. However, much like the Game Gear versions of Sonic the Hedgehog and Sonic the Hedgehog 2, they are similarly titled but decidedly different games.

It's a Sonic the Hedgehog hack that includes Tails as a playable character, new/different layouts for every stage, different music ported from other Sega games, double boss fights in some zones and new moves!