Sonic 3 & Knuckles: The Challenges is an award-winning hack of Sonic 3 & Knuckles by ColinC10. In this hack the player must complete various levels from S3&K, which newly feature specific challenges to complete, e.g. collecting a certain number of rings or protecting Tails from danger. Completing challenges unlocks more challenges, and players' progress is automatically saved to SRAM.

Sonic 3 and Knuckles Time Travel is a Sonic 3 and Knuckles hack made by Jdpense featuring :- New menu screen (WIP) - The ability to time travel like in SCD (ofc)Credits:- Stealth for SonEd2 (newest version)- Xerowhirl for SonMaped- Flamewing for the improved S3k Sound Driver

Sonic 3C Delta is a hack of Sonic The Hedgehog 3 (& Knuckles). It is a compilation of early/unused content for Sonic The Hedgehog 3, including early music, layouts, graphics, concepts, and more.The hack currently includes all the zones from the first half of Sonic 3, including Flying Battery Zone in its original placement and the 3 Bonus Stages.General Changes:Original zone order.Improved prototype soundtrack.Prototype inspired level layouts.New title screen and menu art.New cutscenes.Prototype graphics and art.Credits:Programming:Chainspike, SyntaxTsundere, Rivet, Inferno, Zummone, Fred Bronze, vladikcomper, lavagaming1Beta Testers:MechaKnuckles, sonic c32ttb1, Xebninmaj Sark, Zummone, Inferno, Volbby, JayKuriN, PhoniexVania, Sprite, EmmaNerd, SyntaxTsundere, Legobouwer9, Rodotnik, Sumi, GigglyManGraphics:Chainspike, MechaKnuckles, Volbby, Trickster, SyntaxTsundere, BladeOfChaos, mcginnis03, Hexagonal, JoeyTheRabbit, EmmaNerdSound:Chainspike, MechaKnuckles, Inferno, Flamewing

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!