This was really good! I liked the style, the platforming, and the enemies!
I did notice that the jump is usually fine if there is no blocks in the way. But it made platforming more difficult when there were blocks in the way. Specifically, pressing the arrow keys mid jump undercuts the full jump height. So when blocks where in the way and I needed to jump over it, I had to let the full jump complete before I moved. It is not very intuitive but it wasn't a deal breaker at all. It just made the game a bit harder to complete than without.
Otherwise, this could do with more levels as it was fun to play! I really wanted to do more xD