I had a feeling the game was going to be over after one boss fight...
It's a good attempt at a bullet hell game, you have some very interesting attack patterns for the bad guy.
For the future, I would suggest making the art pop a bit more because all the visuals feel kind of flat, a drop shadow on everything would help. I would also add more audio cues for things like jumping and moving, add controller support to make the game easier to get into.