Knuckles was one of the few secondary characters from a game to get their own game (Zero the Kamikaze squirel was another). Sega saw something in the little red echidna, enough to warrant at least one outing of his own. Too bad it was on the ill-fated Sega 32X platform and not the much better received Sega Saturn, that hit not too long after.
Setup much like the Sonic games, Knuckles Chaotix is a 2D side scrolling action game with colorful levels and a big fat mustached balding mad scientist in a contraption trying to take over. You could almost do a color swap of Knuckles to the trademark Sonic blue and it would barely be noticeable- it would simply seem that Sonic got some new powers.
That is not a bad thing, being like Sonic, what hurt Knuckles Chaotix the most is the platform it was released on. The Sega 32X was never a powerhouse in sales and it took down some great games such as this maiden outing of Sonic’s sometimes rival. Why Sega did not release Knuckles Chaotix on the Saturn is beyond incomprehensible- the Saturn never got a full blown official Sonic game (3D Blast was WAY removed). Chaotix could have flourished on that system, possibly being responsible for a new series for Sega.
Knuckles Chaotix, or just Chaotix, is only available on the Sega 32X, it has not seen re-release other than a short run on Gametap in 2007.