1 minor criticism.
I really enjoyed the game. Art and gameplay were fine, and I even enjoyed the song. The one thing I would change would be the duration of the dash move. As it is now once you build up 4 acorns you can pretty much stay invulnerable to the end of the level. If you shorten it a little so you have to time it just right to destroy the obstacles I think it would add a little more challenge to the game.