Great game! I love the visual style, the concept, the music and the theme. I was especially pleased with the implementation of ZERO UI (volume buttons are very creative LOL).
I want to note that unfortunately I was only able to reach the second boss (I'm too much of a casual player). I would like that after the jam, not only bosses, but also regular enemies would appear in your game (if you already have them, please correct me). It would also be cool if the game added something like character development and random generation. These are just my wishes and this will not affect my rating.
Good luck in developing the game!