This game was fantastic! I love the art style and the music/sounds so much. It's nice and somber without being hard to see. The gameplay is very solid as well, though it is a little sad there's not much variety in enemies, nor much to do after beating the boss other than racking up a high score.
The boss was easily my favourite part of the game, though! I was a little confused on how it appeared at first, but otherwise I had a lot of fun. It's very challenging, but not unfair.