There's a lot that this mod does. Sonic's new thok is very powerful, but it does require speed and cannot be used as a double jump which is good. Tails flying is much better as it is faster in pacing. Knuckles feels much more fluid. Amy becomes a very fun acrobat, though I think removing the momentum redirection with the hammer spin would be good as Sonic is primarily known for that. And fang becomes a fun character to use being able to shoot midair.
The recoloring to the characters are very nice, though I think Sonic looks like he got the most treatment out of it. I see some outlining issues that some Amy and Knuckles sprites have, but that's not really a big deal. Having hyper forms is awesome, even if it completely breaks all forms of level design. Running on water, and uncurling form a ball is always going to be useful, even if its niche. I'm mixed on the trick system because it kinda gives me free speed, which is useful for characters not named Sonic, but it feels too easy. Maybe increase the rotation speed to make landing more difficult.
This mod does have negatives that I would like to see improvements on. While running down slopes to gain speed is fun, the acceleration is way too much. It can make some slopes difficult to control as you just zoom off with little control compared to rolling in vanilla. I also think the maintaining momentum part also needs to be improved for characters with dashmode. I wouldn't care for custom characters, but this affects vanilla Metal. While maintaining dashmode midair makes Metal more consistent, it makes resume to his current speed way too fast. It's not the only factor, but it is the main one, and it does cheapen the feel of his momentum
Overall, this is an awesome mod that can still be improved upon. If those flaws have been changed or fixed, I will give my fifth star.