Interesting and fun moveset, but could use some edits to make it more viable for a platformer.
The wallhit mechanic is a neat concept but I feel in its current form it takes control away from the player. I would suggest reducing the strength of the rebound, increasing the vertical boost, and having the rebound only occur if the player is holding spin. This would give it more of a situational edge and allow the player to control when to use it. Also, it might be worth looking into allowing unlimited rebounds or at least giving the final rebound the strength of a normal one.
I don't have much to say about the Marble Dive. It's a unique spin on one of Sonic's iconic abilities. Though, I was expecting it to give me a vertical boost if I touched a wall while charging it like in the Marble Blast games, so maybe that could be implemented. Also, it could give you more speed if charged for longer. (Is it intentional that charging a Marble Dive prevents bouncing off walls?)
All in all, a fun mod and a cool reference to one of my favourite platformer series. I'm excited to see how its development goes in the future. Maybe some of the more advanced tech from PlatinumQuest can be implemented?
i am, also, partial to very snappy platformers, but a huge part of it is that i don't want the player to stay in the air *too* long. the gravity when falling is exponential for a reason and it's not just because of feel
just for a tangible example, despite the increased verticality, it's pretty difficult to make that one skip at the start of acz1. that's intentional, i tuned the physics partially around that jump