I think the game is highly reminiscent of cup head in a way with all of its hand-drawn elements. I found it a little too easy as I was able to just keep spamming the space bar to shoot. The rate of fire was also a little slow for me. I think you should adjust that a little and perhaps make the difficulty harder with the enemies shooting more projectiles at you. The art is incredibly well done and the variety from the bosses are cool as well. Definitely make more enemies.