First of all, this is amazing. I love all the options, all the moves feel fluid, etc. However, I feel like there are a few things I would have changed.
1: Characters have too many moves. I know that it's hard to decide on an appropriate moveset when lots of moves gel really well with a bunch of other ones, and once you have 3 buttons it's hard not to take full advantage of every combination, but I think a few moves really rarely get used.
-a: the Bounce is a decent idea, but in practice it's only needed in a tiny amount of situations, and in those situations it requires extreme precision to even do what you want. I think it's a really cool idea to have a move that can increase the height off springs and can cause you to rebound off the ground, but I'm pretty sure that a move which increases your drop speed dramatically isn't a great idea in a game where the player depends on the floaty jumping physics to be able to easily target enemies and terrain. Maybe instead, moving at Peel-Out speeds would make you spring higher.
-b: The drop dash being for both characters also feels unnecessary, considering the power of Tails' flight. Maybe instead, Tails should just have a flight cancel which lets him recurl.
-c: Since you can't crouch while moving anyway, why not map that to Spin and make the Spindash a bit more like the classics? If you double tap and then hold Spin, that would give you a Peel-Out. That brings the button count back to two for gameplay, while still keeping two buttons for emotes and character interactions.
2: The Peel-Out charging instantly feels a bit weird, and honestly I never really used it, instead just using the Spindash to get to Peel-Out speeds. I think a better idea would be that the Peel-Out starts you at zero charge, and it gives you more speed the longer you charge it (hold the button), capping out at a speed much faster than the Spindash. To stop people from turning it into a faster Spindash, maybe you can't curl for a little bit after using it. This would make it worthwhile to use.
3: Water-traversal speed should be increased to vanilla level. In addition, the Peel-Out and Spindash shouldn't be completely unusable underwater. Maybe they should be kept to normal levels, but the speed cap underwater is just much lower. This is mostly because the Drop Dash doesn't lose any power underwater, and in fact, due to the floatier jump, becomes OP.
4: On keyboard controls, the Momentum Flip should keep itself closer to the direction you were last going in, so that you don't fly backwards when you want to make a sharp turn. Analog controls are fine without this change, since controllers have more precision, but on a keyboard you're out of luck.
Everything else is really great. I love the Momentum Flip's versatility, and the flight meter should be in every Sonic game. I especially love Pointy's version of the Peel-Out, because it does what I've always wanted with the standalone version, where it activates the after-images at any time you reach a certain speed, not just when you activate the move. Great work! Also, sorry this comment is so big.