Great job! The controls were good, which is great for a platformer. I eventually got lost and couldn't figure out where to go -- I thought I was going the right way but teleporters just kept taking me back to the beginning -- so I couldn't get to the end of the game. Also, several times if my speed was too high I'd clip through the floor and get trapped inside (I would have to restart) -- so maybe adding a max speed to your character might prevent that (or increasing the physics tick rate. Some music would be nice -- free CC0 licensed tracks can be had in a lot of places (e.g. freesound.org). Also, I noticed some of your sprites had black backgrounds that would draw over other enemies, etc -- it'd be nice for those parts of the sprites to be transparent.