The belts look scary. I thought I was being hexed or something when I first encountered them.
When I ended up down a hole with what I now understand to be the belt I figured it out ball mode (it's 's', not 'd').
Nice music and sounds. While I am rubbish at football and precision platformers, I like the novel physics here.
You finished your level, and acknowledged the player for doing the same. That means a lot to most people.
The rolling jump was really fun (but probably because it's OP). The platform hopping, not so much.