Going to put this in sections as each character is a unique playstyle (spoiler: im not gonna call the abilities by their actual names because i forgot them, sorry :P)
starting with..
Espio:
His moveset is similar to that of Junio Sonic with a hint of Shadow, as the teleport is aimable though most wont know unless told. It would be nice for him to get a camera control option if possible. Everything else is literally one of the better movesets i've seen since Modern Sonic and Mario Bros. Not much to say about his sprites as they're almost all the same as the previous Espio, but they're still good, so don't fix whats already working.
Mighty:
Theres not much to say here, he has quite a simple moveset consisting of a slam and walljump. The walljump is based off of momentum, though that means that if you dont time it correctly he can drop way down, which brings me to the slam and well.. It's alright, i guess. It works well but quite annoying when you want to walljump as they're both bound to jump. It would be nice for the slam to have an alt bind option. His sprites are really well made, too.
Charmy:
The smallest character of the pack, but my second favourite moveset. His moveset is mostly movements in air, with an upwards move and a downwards move. The upwards move is based off of your direction, without moving it bursts straight up but with moving it goes diagonal. The downwards move works the same, but points downwards instead and has you bounce off of the ground afterwards. Overall, his sprites arent the best i've seen but they're still pretty well made with being so small.
Vector:
A larger character that cant easily go into small crevices while rolling, but much more balanced between aerial and grounded speed and height. His roll acts like an accelerate than an actual roll, having much more control than the original roll that Sonic and co have. It can drift slightly, and turn too, making it one of vectors most useful abilities, right next to his wallbounce ability, which can bounce off of walls infinitely but only if timed correctly as you have to hold down and let go at the correct time to trick and chain more bounces. Fail it twice and you cant use it again. My favourite one out of this entire pack.
Heavy:
The Wario-Like character, sacrificing air mobility and control in exchange for speed. His Mach Run is incredibly fun to move with, but it doesnt go that fast. He can also dash like the Shoulder Bash from the Wario Land series. His jump is unique as its a hold move thats better the more you hold it. He isnt the best in the pack, but one that i wont forget any time soon.
Bomb:
Alright, how do i explain his moveset.. Its really special and unique is what i'll say. His spindash contrasts Heavys jump, as its incredibly different compared to what Sonic would have, as it can be charged mid air and on ground, including having a special effect that shows if its fully charged or not. He has a jump ability, a forward dash that is charged similarly to his spindash. If you charge it to full, you can go into a wall and launch yourself up, in which Bomb quite literally strikes a pose before falling back down. Similar to Heavy, he isnt the best of the pack but is fun to play as.
Overall, The Chaotix are an amazing pack that i would recommend to anyone starting out. An easy 5 stars from me and i hope that this can lead to more characters and maybe even revamps of existing mods, like with Espio and Mighty here, being made in the future.