Welcome to releases! I do like that you've given new abilities to Sonic, Knuckles and Amy here, they're pretty nice. Although Sonic's is pretty hard to control at times, and holding down Custom 1 as Knuckles while gliding basically lets you fly across the entire map.
I do kinda wish Tails, Fang, and Metal Sonic also had their own abilities, as of right now their changes don't really impact much of anything. Also, Metal Sonic accessing Knuckles paths doesn't really do a whole lot for him, since he's still incapable of taking most of them. If you can add new abilities to the rest of the cast, I think this would improve this mod by a long shot, and make it feel like a proper complete package.