The art style is amazing, but the controls are dragging it all down. The movement feels unresponsive, and doesn't do what I want it to do. Also, the fact that you can't attack while in the air really hamper the options you have. All you do is wait until the boss comes down to attack him once, and he flies back up again. Also, the fact that both the entire-floor-becomes-spike attack and the horizontal high laser have the same signal is quite unfair to the player.
But non the less, it is impressive work from a single person, and I hope you are happy with what you achieved.