Knuckles' Chaotix (32X) ROM

Sega's 32X add-on for the Genesis/Megadrive might have been an ill-fated product, with only few games produced and a short lifespan. However, of all that library, one lone game shines with its own light.
Knuckles' Chaotix, a 1995 game set on the Sonic games universe, lets you play with Knuckles and friends with a whole new different gameplay mechanic, colorful worlds, and great music. The game is set in the new Attraction Park/Fair created by Dr. Ivo Robotnik (Eggman in Japan) by turning animals into robots (once again).
Sporting the new combi system, Chaotix forces you to play with 2 characters in screen, connected by a string of stars generated by two rings on the character's hand. This allows for both a very frantic or a difficult and hindered gameplay. The game still looks and works as a regular platformer, with each character having pros and cons. Knuckles can glide and climb walls, Mighty can attach himself to walls and double jump from them, and so on. But the combi system makes everything a bit complicated or easier. Using it you can reach heights by grabbing your partner and launching it towards other platforms, or you can stretch the string and then let it go to get a huge boost. Some puzles can only be solved by controlling your partner in several ways, and if your partner becomes entangled, you can pay 10 rings to return it to your position.
This time you don't get Chaos Emeralds, but Chaos Rings instead, big colored rings hidden inside of 3D tunnels in the Special Zones. Get those 7 Chaos Rings, and finish all zones, and you should have completed the game.
Did you know that some of the gameplay mechanics were explored first on a (really incomplete) prototype named Sonic Crackers? Go check it out.
Having 5 zones with 3 acts set on different times of day, and a final showdown against Robotnik and 5 partners to choose from, Knuckles' Chaotix is a rather short but interesting game for a really ill-fated contraption. It's a must-play for any Sonic fan.