Sonic And The Mystic Gems (previously known as Sonic 1 Harder Levels) is a hack made by Eduardo Knuckles and his team Harder Project of Sonic the Hedgehog on the Sega Mega Drive. It began in 2005 with the simple purpose of being a generic Sonic 1 for Sega Genesis with increase difficulty and revamped versions of the original levels. But now, it's going to present a completely new gaming experience with a new style of level layouts full of paths everywhere among new enemies, new objects, new character abilities, new menus, completely different styles of the Sonic 1 special stages and much more!Credits and Special ThanksMistergambit for his Spring Yard Zone and Labyrinth Zone level art used in the game.Tweaker for his information regarding music importing, bug fixes and the speedcap removal.HPZMan for the new sound driver instruments and the dynamic tile-set system.Selbi for some new exclusive ASM things and improvements.Master3k for sending and fixing some music.nineko for creating the xm3smps tool which was essential for the creation of some songs. Special credits to him for the different songs per act system used.SCAA for their art.Puto for his tutorial to add Spin Dash.FraGag for his tutorial to fix the spike bug.SonicVaan for beta testing.HCKTROX for the lead programming and bug fixing.GenesisFan64 for the save screen menu, for some fixes related to the fade-out and others.MarkeyJester for lots of important code and a whole load of others.Irixion for beta testing.PsychoSk8r for his the dynamic palettes tutorial.Esrael for fixing essential things in the new sound driver.Prilix Bõkun for bug searching and beta-testingEstlib for various art stuff related to levels and for additional help with creation of gimmicks and objectsDJ. Joker27 for his very big importance in specific level and misc musicMighty Arnold for additional support with beta-testing and level layout designKenny0989 for additional support in the music department Special credits to Harder Project's Team by all the useful exclusively things used in the project.

Sonic CaDa is a hack of Sonic the Hedgehog by CamManS5.This hack features, new music, new art, secret paths, and multiple end points in each level that offer different rewards. The Special Stages have been changed into Bonus Stages. There will be new Special Stages based on the 2D Special Stages found in Sonic Triple Trouble. Since the new Special Stages are not implemented yet, the Chaos Emeralds cannot be collected at this time without cheating.

Sonic Chaos Quest v2.0 is a modification of Sonic the Hedgehog. Story:Exploring Mobius seas Eggman found the Chaos Island. It has giant lake, on bottom of which the sunken ruins of Chaos Shrine which contain the inexhaustible power of Chaos are lying. In order to increase the power of his mechanisms Eggman built the Hydrostation on this lake and plans to conquer the world with the power which he got. Residents of the island asked Sonic for help, so he teamed up with Mighty, Tikal and Metal Sonic to start their Chaos Quest to stop Eggman's evil plans once again!Credits:Programming: Narcologer, Vladikcomper, TheBladNew level art: Narcologer, ShooterNew chunks and layouts: NarcologerSprites: Narcologer, The Spriters Resource, SCAA, Lone DevilMusic: Ivan YO, EgorTC, Nineko, TheBlad