What an incredible work. I like that you included a tutorial for the game.
I really like the hand made design all the way long. The game is a little bit difficult to familiar with but as you play it is ok. 3 bosses to beat (at least) and a reminder of the 2 first on the last one, i love the idea.
The last boss is really tough ^^'.
The audio part is also great it fits totally with the theme.
Good job!