I really enjoyed playing through this, I did a full playthrough with Sonic on a no save and it was a really fun extra challenge that is (for the most part) fair. I personally do think it needs some changes for what decides whether 2011x can or can't spawn (like making him unable to spawn in the anti-gravity segments in black rock zone, or the ropes(?) you hang onto in Arid Canyon Zone) and potentially not making him spawn the MOMENT whatever is stopping him from spawning ends, it makes the part where the you have to be holding onto something or you get pulled into space drag out for way too long, and I was barely able to actually do it purely because I used the thok so I have no way of knowing if it's even possible for Amy. I also really dislike the interaction between Super Forms, you're not much better off in Super than you are out of Super most of the time, but then it completely nullifies rage basically, to me it'd make more sense if he did the ring draining grab during rage but outside of rage gets stunned before they can hit you, maybe even make it increase rage more than a normal stun. Hitting you through I-frames is a bit too much, he spawns often enough where I don't think being invincible during invincibility frames is too much to ask. Already mentioned him being buggy with ranged moves in discussion, but he's also buggy with many other things like Kris' lunge, MC Amy's heli-hammer, MC Tails' tail-swipe moves or (for some reason) specifically the 2nd or 3rd uses of SMS' kick attack the (1st use works fine) are all examples I've come across of moves that, despite destroying badniks, damaging bosses, etc. just don't stun 2011x for some reason. I also wish you could use homing moves (I would LOVE to obliterate 2011x with a comet haymaker lol), especially for the sake of Fang who would probably be absolute suffering to play with this mod rn, and parries on him though, it aint like charge nullifies knuckles' counter, so why should it nullify srb2 counters? To be honest though, all the base game moves work fine, though pop gun barely does and we definitely need homing to work, so complaints about some moves not stunning aren't that big since they are mod characters and not base game characters., everything else still stands though.
Overall, even though I have a long list of stuff, most of them are small complaints or just because I want to be able to enjoy the mod with more characters and movesets, really do recommend it, it's super fun.