The game is freaking beautiful. Gameplay is fine, I think everything is pretty good except the last boss, the only one I beat in one try, and his big laser is a cool concept but very easy to manage, maybe add some bullets or a second laser I don't know but it's a bit too easy for now...
I prefer an almost impossible final boss that double the life-length of a game rather than a one-try final boss (even if he is pretty epic).
Also there is a little bug that make your lifebar escaping from the left of the screen, maybe it's because I started with the dragon boss (on my second try to see if the game had a savestate), I don't know.