Sonic 1 Special Version is Sonic the Hedgehog hack made by EditChris.This hack add new level layouts, New Art, A lot of ASM changes/add, MegaPCM driver improved and a lot of music added.

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.

A Hack Based on Sonic 1 made By RoxurfaceSonic 1: Contemporary attempts to breath new life into the art, music, layouts, and abilities available in Sonic 1. Minor art changes have been made, mainly those found in the 1.1 version, and other minor details. The palettes have been updated to be more lush and vibrant, and each act has a variance of the original zone. The first act retains the original music, and the other two feature variations akin to Sonic 3 & K and Sonic Mania. The exception is Labyrinth Zone, which for now has the same palette and music across all three acts.Sonic can spindash, peel-out, and wall-jump. With six Chaos Emeralds, he can also transform into Super Sonic. (Though without the seventh emerald, the golden form is replaced by invincibility stars, and the level music continues to play.) To become Super, collect the emeralds and 50 rings and press "C" while in the air. You may also revert back to Sonic's normal form at any time by jumping and pressing "C" again. The form otherwise functions exactly as in Sonic 2. The level designs are left mostly faithful to the originals. However, there are now many new shortcuts and secret areas that can be found, especially when making use of Sonic's new abilities. There are plenty of ramps to peel-out off of, and many tight walls to ascend. Marble and Labyrinth have had the most drastic changes to encourage more of a flow rewarded to skilled play. You can even complete Labyrinth Act 2 without ever entering the water. I issue a challenge to all players: in each stage, there is a 1-Up monitor in a new location (the original placement of the 1-Up monitors has been removed or changed to a different power-up.) I challenge you to find the 1-Up monitor in every stage! Bonus points if you collect every 1-Up in a deathless run!This hack was made using Mercury's ReadySonic, so many of the bugfixes and features from that project are present.The bosses in the original game were already painfully easy, and now Sonic's new moves have the potential to make them laughable. To account for this, the good Doctor's Eggmobile now has more invincibility frames. This makes the boss fights more about rhythm and platforming than just wailing on the machine. This affects only a few bosses, mainly in the first half, but I believe it adds a new layer of depth to the bosses.