During my second run I lost all my remaining lifes failing the tricky jump with the wall descending between the two platforms in the beginning of the level with the black background.
The game is a bit rough although the only thing which I think is kind of critical (but the game is playable anyway once you figured it out and are careful) is how you sometimes can't jump because it might take a while between the moment you fell down close to the floor and the moment you're actually touching the floor.
However that aspect aside the game controls well enough and at a fitting speed and the, many, levels are good with fun and different sequences to go through and an appropriate difficulty for the jam.
Among small things I think you can only choose between the original resolution and full screen mode, there could be a way to increase the size while keeping the pixel ratio. The character also doesn't move with a moving platform he's on which is weird.
Thanks for sharing!