Good review there. Helps me come up with stuff to update in the game.
I can agree that the bosses have unnecessary amount of health, just some of their attacks are tied to their current hp. I'd need to adjust that as well.
Technically you can keep holding the attack button and the player will keep shooting, but at a very slow rate. I'm hoping that the shop/upgrade system I'm planning to add will help with making the game more accessible for people of varying skill levels.
Oh yeah, and those eyes, gotta fix em.