Good work with the camera and level designing. My main feedback would be, that you should have concentrated on short working prototype first. Sure, you have 9 bosses, but what's the point, if player can't die and can skip them? So you could make 1 boss fight first: make it so player can defeat the boss and boss can kill the player; make so player can't skip the boss fight, until player defeated the boss; add music and sound. Then this 1 boss fight can provide much better gameplay experience.