Good Entry! I think the idea of falling and having to get back up to continue is super unique. I think you could improve the game a lot by fixing the slopes as they aren't very smooth for movement and jumping off, and fixing the platforms. I think both of these are pretty common issues. Look up coyote time for the platforms and check out this video (or a 2d equivalent) for the slopes. Additionally i would maybe put a one way collision on the platforms as it is quite frustrating hitting them with your head.
Good entry!