Very good game, great art, love the Cuphead inspiration, gameplay is fun and challenging. Use of the theme could use some work, right now there's no reason not to use your lives to attack, after all, you cant beat the boss without attacking. If i was to make a suggestion on the mechanic I would say have the boss go down on a time limit, with the damage the boss takes speeding up the time till there defeated. that would mean using your attack is a rewarding gamble, do i waste some of my life and risk it all to defeat this boss before I die? either that or just add boss checkpoints. Anyway enough rambling, your game is great, had a lot of fun playing it.