Sonic the Hedgehog Plus (often called Sonic 1 Plus) is a hack of Sonic the Hedgehog by Hivebrain. The hack is basically the same as the original game, except with a number of extra features and bugfixes.

Sonic the Hedgehog Thrash is a ROM hack of Sonic the Hedgehog 2 by DalekSam, though it was originally a hack of Sonic 1. It also uses the Sonic 2 Clone Driver.You can also play as Knuckles, credit given to Spanner for the Knuckles object among other things. Honestly, I tried doing it myself but I failed, hard.As of August 2013, the project has since been rebooted from scratch.

Sonic The Hedgehog ZX (also known as Sonic 1 ZX or S1HZX for short) is a hack made by CarrascoZX0 and his team, Team ZX. This hack features the ability to play as Sonic the Hedgehog or Knuckles the Echidna. The hack also features new art, abilities, level layouts, music and much more!

Sonic the Hedgehog Extended Edition is a hack in progress by Cinossu of Sonic the Hedgehog on the Sega Mega Drive/Genesis. In this version of the game, instead of new or fully edited zones, all the original zones are kept intact with minor editing to the acts. Instead, this hack extends the game beyond its original capabilities, including a zone map with warp rings to each act (much like in Sonic Advance 3), saving via SRAM slots (like in Sonic the Hedgehog 3), obtainable upgrades such as the Spin Dash and Super PeelOut (like in the Megaman X series) as well as a new type of ring, emerald, and special stage to add to the mix.While work has not been shown on the hack for a while publicly, a lot of work goes on in private. This is mostly Cinossu either restarting the entire thing from scratch (currently on the 5th restart since conception), or constantly adding and refining new features and ideas. The latest restart is most likely the last one, however, as the disassembly is now so modular that the various chunks can be restarted rather than the entire hack.

Sonic the Hedgehog: Isle of Magnetic Artifacts is a sonic hack made By Neo Team Kyukyokuis a hack which aims to overhaul Sonic 1 using a Japanese-inspired aesthetic. The main feature of this demo is Blossom Gardens Zone, the resting area of the isolated, star-god worshipping Kuratranos tribe. BGZ is a fast-paced experience littered with swift-acting enemies, height-granting gimmicks, driving music, and advanced graphical effects. This new zone can be traversed with three playable characters: Sonic the Hedgehog, Miles "Tails" Prower, and Knuckles the Echidna. Sonic, in particular, features a set of unique sprites, the dropdash ability, and a new companion: Abbey the Flicky. Abbey can pick up nearby rings and circle potential targets for Sonic, including hidden monitors.Neo Team Kyukyoku MembersAngelKOR64: Character programmingChron D: Music arrangementDeltaWooloo: Level layouts, music arrangement, object ports, programming, sound effectsDaxKatter: Music arrangementDio-ZX: Character art, object artDrag109: Level artfuzzy: Level art, programmingiced t: Level art, object artInferno: Level layoutsInktitious: Level artJerry: Level layoutsKatKuriN: Level artKGL: Level layoutsKurk: Team Leader, level layouts, music arrangement, music compositionManiacShard: Object artNaotoNTP: Object artProjectFM: Creative direction, level art, music arrangement, music composition, programming, story planningRaendom: ProgrammingRivet: Programmingtwo^: Concept artyami: Level layouts, music compositionFormer MembersAmzroSevca: Concept art, story planningGemini0: Former team leader, general art, level layouts, programmingjrm1007: Concepts, object artHaz Rabbit: Concept art, programminglavagaming1: ProgrammingNotQuiteHere: Music arrangementpoly: Logo, music arrangementMr. Gandy: Character artXGSOAP: Character artPlaytestersAccelBladeOfChaosCertainly GlitchyCosmic EternityDaxKatterfengishGGK912Hooded EdgeKCEXEKNIJohnMattyMeara BlanchetteMCTravisYTProfessor RendererPXSleekflash-16Sr ParadoxosoapyyTheInvisibleSunUnusualSeekerResourcesAsuharaMoon: Wind-Up Koi spritesAURORA☆FIELDS: SMPS2ASM and AMPSCartoonsAnimate22: Tails and Knuckles spritesCuckyDev: GHZ ball baseflamewing - Ultra DMA Queue + optimized Kosinski (improved by vladikcomper and MarkeyJester) and Enigma decompression codeLone Devil: Metal Sonic spritesMainMemory: SonLVL and Drop Dash programming guideMarkeyJester: DualPCM and sound testMikel Nash: Sonic 3-style super sonic spritesObserver: Sprite ripsShibaMayo: ShibaSaturn spritessnkenjoi: Flex 2The Eighth Bit: Space Queens MIDITheOneMusaab: Sonic 2: The Alternative Spritestildearrow: FurnaceTeck: Super Mario Land - Ending Theme MIDIvladikcomper - optimized Nemesis decompression codeValleyBell: mid2smps, SMPS Converter, SMPS Research PackVladislavSavvateev: DMF2AMPSAssets From:Capcom no Quiz Tonosama no YabouCave StoryFreedom PlanetHigh Seas HavocMega Man SeriesMichael Jackson's MoonwalkerRistarSangokushi Retsuden: Ransei no EiyuutachiShinobi IIISonic SeriesTouhou Project Series

Sonic the Trollface is my Sonic the Hedgehog hack. I've been working on it for about a year now, on and off. I started it on a Windows XP Virtual Machine on my iMac, until I finally sorted out my computer. The demo started as a mini hack, where I tried to make the game as difficult as possible by changing mechanics. I'm pleased to say it's nothing like that anymore, and is a lot more forgiving (though you most likely won't be speeding through the stages, unless you are Razor and Zenon - then you will be :P). The goal of this hack is to provide a fun twist on a tired formula. I won't give away some of the edits, but they are pretty cool. It does make it a bit difficult, but I believe in you! You can win the game! Rather than trying to speed through stages and rack up rings, instead you want to try and speedrun the tricky maneuvers in the stages. You've seen hacks that spam enemies, and this isn't one of them. Difficulty should come in the mechanics, not by having too many dick moves in the levels.