Sonic Boom is a total modification of Sonic 2, created by snkenjoi and iojnekns, along with a wide array of talented contributors. As of the Seventh Annual Hacking Contest, this collective is referred to as SÆGA.

Sonic 3 Complete is a hack of Sonic 3 & Knuckles which aims to provide a much improved variant of the original game, with many new options and features, without straying from the original levels or gameplay. The inclusion of separate modes for Sonic 3, Sonic & Knuckles and Blue Sphere also make this a close cousin of the PC compilation Sonic & Knuckles Collection, albeit designed for the original 16-bit hardware.

Sonic the Hedgehog Megamix (commonly shortened to Sonic Megamix) is a work-in-progress multiperson disassembly modification of the original Sonic the Hedgehog videogame for the Sega Mega Drive / Genesis, developed by Team Megamix and more recently moved to the Sega Mega-CD. The game features the ability to play as one of five different characters: Sonic the Hedgehog, Mighty the Armadillo, Shadow the Hedgehog, Miles "Tails" Prower, and Knuckles the Echidna. It is an extensive reworking of the original game, featuring new art, music, abilities, layouts, and other things.

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