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.

Sonic 1: Painto Edition 2 (or simply Sonic: Painto Edition 2) is a modification of Sonic the Hedgehog (16-bit), and the first part of the Paintifisation project, made byPainto maniak. The hack contains many features, and is named 'Panto Edition 2' to separate itself from Painto maniak's previous hack; Sonic: Painto Edition (later renamed Sonic: Christmas Island).

Sonic 1: The Special Stages is a hack of Sonic 1 by SonicVaan. This hack removes standard Sonic gameplay and replaces it with the Special Stages which normally were only accessible by the Giant Rings at the end of each stage.The actual special stage layouts have been touched for every stage.This hack is actually on hold. Future releases are not to be expected.

Sonic 2 Adventure Control is a hack of Sonic 2 by MainMemory. It changes Sonic and Tails' movesets to be similar to Sonic Adventure.

Sonic 2: The Alternate Sprites is a Sonic the Hedgehog 2 ROM Hack which changes some of Sonic's and Tails' sprites, including Super Sonic (however with Super Sonic there is a glitch, which causes crashing after falling from a spring). Credits: The One Musaab - Spriter, Implementing Sprites

Sonic 2 Armageddon Game is a hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by xenoSonic. The layouts of the first four zones of the game have been altered, with the rest of the original levels unaltered. Additional levels are planned, but as yet are not implemented.

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 2 Delta is a groundbreaking series of ROM hacks by famed Sonic scene member Esrael Neto, which restores several deleted levels and prototype elements to Sonic the Hedgehog 2 for the Sega Mega Drive / Genesis. Various features of Sonic 2 Delta, common across the series despite the existence of several versions/branches of the hack, include the use of art and music from the betas and Sonic the Hedgehog and re-implementation of badniks that had been removed from the final game. The level order of Sonic 2 Delta is also similar to the original intended order, rather than that used in the final version. The main version of this hack is entitled Sonic 2 Delta and was based upon the Simon Wai prototype, before version 0.24 transferred the codebase to 'revision 2' of Sonic 2 from Sonic Compilation. More information on the various lineages and their history is detailed in the section "Other versions" below. A hack similar in concept, called Sonic 2 Long Version, has been released by another hacker, Sonic Hachelle-Bee.