Firstly I wanted to say that I think a mushroom on a skateboard is cute. I do not know how you associated those two things, but it is adorable.
The game mechanics themselves were kind of hard to figure out it felt kind of bad to try to speed up in the starting area and get out of the hole because I kept bouncing all over the place. I would say that with the tight jumps and the slow build-up in momentum, this game would have benefitted more from an open-level design that lets the user build up speed and fly through levels rather than precise jumping levels.
Also designing the jumps so that lets say when you bounce from one wall to another that it actually gets you to another platform on the level. I know you did that a bit but it would've been nice to see it more. Or if it was intended to be done that way to be a bit more clear.
interesting idea!
-R