I really enjoyed the game! It took a little bit for me to get a handle on the controls, but I think I got a handle on it. Still was a bit challenging, which is definitely partly a skill problem on my end. The art and music had a cohesive style!
I might suggest removing one or two of the initials bats to give the player more of a chance to get a handle on the game and get that first power-up, but otherwise if this is intended to be a difficult game, I think it provides a healthy challenge. Well done on the game!