gorgeous soundtrack, probably the nicest looking pixel art for a sonic game on the genesis, and just absolutely atrocious gameplay. almost everything knuckles chaotix does is for the worse. the stages are massive and vertical, almost like an unholy marriage between sonic 3 and CD, but unlike those games, there's little to nothing in the way of platforming difficulty here, virtually no gimmicks, nothing. enemies are very few and far between as well, and rings are literally everywhere, meaning the difficulty in chaotix is beyond low. the high ring count is cool for a little bit because it makes the special stages more manageable, but you'll be done with those pretty fast, at which point rings no longer serve much of a purpose... because lives don't exist. this is actually a pretty progressive idea for a game from 1995, but in tandem with the level design it makes progression feel pointless and dull. after a while, you realize why the level design is like this; it has to be big because proper use of the tether mechanic (or just picking knuckles or charmy) allows you to basically fly straight through everything otherwise. it has to be empty because level selection is randomized, so they don't want to turn up the difficulty out of nowhere, and they don't want to shock you with gimmicks you may not have been properly introduced to. it is extremely impressive that this game manages to have 5 distinct zones, complete with day and night cycles, that all manage to feel like the exact same sugary slop.
the tether mechanic itself has some cool ideas, but because of the difficulty simply not scaling in this game, you're rarely if ever forced to use it. honestly, even without using stuff like charmy's flying, i would have a lot of difficulty trying to find any situation in which the game achieves something with this mechanic that couldn't be achieved with standard sonic mechanics. yes, you go fast, but sonic games had already mastered speed without feeling like an incoherent, uncontrollable mess. the only real feat chaotix pulls off by comparison is that if you know how the tethering works really well, you can completely trivialize the levels... but the levels are already trivial. the most use the game gets out of the fake co-op is literally in the tutorial.
anyways, the special stages are really nice and probably the best reason to play this game. not the best special stage of this era, sonic 3's is still better, but very solid.
the worst part of this game is that you never truly feel like you're in control of anything. you zoom though empty corridors, but you somehow feel more hands off playing chaotix than you do during the tube sections in traditional sonic games. what a mess.