Very charming! Reminds me a lot of Celeste and it has a lot of potential, but I also think it's a bit too hard and too tight with some of the jumps. I also didn't understand what to do in that one level with the ball on the spikes and the 'Hold space' message. As a side note, I would let the player use a key on the keyboard to replay a level, as switching between keyboard and mouse can be a bit annoying.