Sonic 2 Time Attack is a hack of Sonic the Hedgehog 2 (16-bit) by redhotsonic. It goes without saying, but it will be said regardless: This a Time Attack edition of the game, in which the object of the hack is to play through the zones/acts of Sonic 2 as fast as you can and set the best time records possible. Once you've completed an act, the game will record your time, provided you beat your record.

Sonic UMZ is a hack based on Sonic 2 made by Trinitronity

Special Thanks given to:
MainMemory: SonLVL
Ezrael: Bugfix on how to make Sonic retain his rings at a checkpoint only after exiting a special stage.

Sonic 2 Westside Plus is a hack of Sonic the Hedgehog 2 that aims to give the beloved game a visual and sound overhaul. Play as Sonic or Miles "Tails" Prower and travel through the four zones featured in this demo to stop Dr. Eggman and save Westside Island! The zones featured are: Emerald Hill Zone Chemical Plant Zone Casino Night Zone Oil Ocean Zone Please note that this hack is in a very early state of development. Expect there to be a few bugs! Credits PRODUCED BY MDREAMS Credits: MDreams: ChiliHog - Team Lead mattm4nia - Musician DarkShamilKhan - Musician Chainspike - Misc. Assets RoBEEFnik - Artist Rojo2010 - Feedback/Misc. Speems - Feedback/Misc. TheBeard - Feedback/Misc. Varion - Feedback/Misc. Bumper - Artist audrey - Programmer Chavão888 - Musician dashlilhog - Artist Dawid - Feedback/Misc. dj green lantern - Feedback/Misc. Hame - Musician HipSnake - Feedback/Misc. NPC - Feedback/Misc. Ramona - Feedback/Misc. sandshowercat - Feedback/Misc. Special thanks to... Laffy Taffy - Sonic/Tails Sprites Nik Pi Hez Nuclear - Misc. Music 4 anonymous contributors Anyone else I may have forgotten to credit

This is a hack based if the original Sonic 2, that has been in the works for quite some time. It includes 4 characters to choose from all with different moves that fit them. Every level in this demo has had a background change, along with new music in each act. Layout changes (Knuckles has some of his own) and much more...

Story: Shadow is back and teams up with Robotnik...

Credits:

Project Leader: JoenickROS
Layout: NeofusionBox, JoenickROS, Markeyjester, Electroball, Shockwave, Bakayote
Music and Sound: JoenickROS, Bakayote, KCEXE
Sounddriver: Flamewings S3K driver
Art: Blazer, Bakayote, KCEXE, Asuharamoon
Minor Coding: JoenickROS
Major Coding: Shockwave, Varion Icaria, Ralakimus
Beta Testers: Mike B Berry, ThomasSpeedrunner, Bakayote, Shockwave, Varion Icaria, NeofusionBox, King of Hearts
Natsumi: Credits Sequence
Special Thanks: Shockwave, and Varion Icaria, without them, I might have not been able to fix some of the coding bugs.

Sonic 2: Advanced Edit is a Sonic 2 hack created by rika_chou. The latest release features 3 new levels. Other (incomplete) levels can be accessed by using the level select menu. As of release 3, Sonic 2: Advanced Edit has officially been discontinued.

Made by Team AE Sonic 2 Advanced Edit features 7 entirely new zones, each full of unique enemies and with a boss whose gameplay varies depending on which character you play as. Playable characters are Sonic, Tails, Knuckles and Amy. Furthermore as bonus content, the hack features the 5 zones from the 2008 release, brushed up to be fully playable. Upon completing the 7 main zones, you obtain a code to access the level select from which you can play the bonus zones by selecting "South Island 1".

Sonic 2: Aluminium Edition is a hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by Dr. Eggfan. It doesn't feature any ASM content nor new layouts, it's pretty much Sonic 2 with a few new visuals, and for some reason completely different names for the same zones. There's also a partially restored Hidden Palace Zone in there.

Sonic 2: Battle Race is a hack of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis by ColinC10 that allows two players to compete with each other on multiple stages. The hack handles this similarily to Micro Machines as the player must reach the edge of the screen first to win a point. Whoever has the most points at the end of the round is declared the winner. A stage select is available without the need for a cheat code. All zones are playable except Sky Chase and Death Egg. Note that this hack is two player only.

Sonic 2: Painto Edition is a hack made by Painto Team for Sonic the Hedgehog 2 as a part of Sonic Hacking Contest.

Sonic 2: S3 Editon is an assembly hack of Sonic the Hedgehog 2 by Alriightyman for the Sega Mega Drive. It places the levels of Sonic 2 into the engine of Sonic the Hedgehog 3; providing many of its features, including Act transitions, a Sonic 3 Save Screen, and Tails ability to fly.

Sonic 2D Blast Is a work in progress hack by Painto Maniak initially started as a proof of concept but with the amount of feed back recieved about the hack, he decided to continue it.

sonic 3 & knuckles – master edition 2

A Hack based on Sonic 3 & Knuckles this is a demo version v0.39 made by Juke Denton

the hack has only complicated bosses.
It's not finished is a beta version. In the future, this version will be much better.
And much more.

This hack made by TheBlad

Sonic 3 & Knuckles Master Edition

Sonic 3 & Knuckles: Pro Survivor is a hack with difficulty layout in levels trying be a challenging game.

A hack based on sonic 3.

is not a demo version of anything, it's just a collection of boss ideas I had, which were inspired by games from Konami. Keep in mind that these bosses are still difficult and you'll need to spend time studying their pattern to win.

There's Quick Start in the game, which is a feature from Contra Hard Corps. It allows for instant respawning without reloading the level.

Credits:
Programming: - TheBlad768.
Music ports: - FoxConED.
Graphics: - Mr.Cat, Dolphman.

External Credits:
Sonic 2 Clone Driver - Clownacy.

Sonic 3 & Knuckles: Pro Survivor it's an palette and layout hack; the point on this one it's to have a extra difficult and hard layout (though fair), with some improved gimmicks.

In the last year, I wasn't very happy with the state of the hack, so this one I decided to give it a better effort and polish everything with my best effort (with new content, of course)!
Unfortunately, it's still just a demo and not a full version. So the 5 only levels available are:
Angel Island Zone, Hydrocity Zone Act 1, Ice Cap Zone, Flying Battery Zone and Sandopolis Zone (unfortunately too, AIZ and ICZ2 isn't ready yet for Knuckles, so I hope you understand).

Also, has a new Main Menu and a New mode (up to you unlock), and in the future will have more features.

Now let's go to the credits.

Credits
Hack Author, Layout and Level Design:
*NeoFusionBox Team

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 Amy Rose is a fan-made hack of the game Sonic 3 & Knuckles for the Sega Mega Drive/Genesis, with character Amy Rose as playable character in place of Sonic the Hedgehog. The games' sprites (modified from Sonic CD) use Amy's initial design prior to Sonic Adventure.

The game was modified by Sonic Retro member E-122-Psi with additional programming and coding by other members including Tiddles, and additional sprite work by ChelseaCatGirl and MotorRoach.