Cool concept and even optional collectibles, I like it :)
The movement doesn't feel great however, specifically the time it takes to get your character to move, and how the jump height is inconsistent. You can't jump as high while moving towards a wall, and you jump higher if you just landed after hitting the ceiling (and you actually need to do that to get away from the diamond in level 2).
We made a platformer as well, but with a loop in time instead of space, maybe give it a try :)