Wow really nice game! There was a real sense of progression to this which is quite hard to achieve in a game jam. I really liked how the game developed over time and it was satisfying to beat its challenges.
The only improvements I can suggest right now is that I found the character's jump to be pretty weak feeling, I'd like it to go a bit higher maybe, and I'd take another look at the collision on sloped surfaces, as it makes you move very slowly and its a bit unsatisfying.