Very interesting submission! Aside from the obvious tips (sound/music), I really liked the pseudo-knockback (maybe you might call it a hit-stop?). That was extremely clever and well-made. I think this is a pretty successful game though, period, and if you were to spruce it up, you'd get people to buy it. :P Only thing I'd mention is it would be nice to get some settings so that you could turn on a color-blind accessibility mode - the colors of things can kind of blend together otherwise and it's tough to see the shield (imo).