I love the art and style. The concept is fun, a bit more content would go a long way but who has time for that.
Enjoyable game, only critiques are that there seems to be a bug where I randomly face the sky or floor when I spawn in, and the transitions between menu, game, and back are too slow for a game where you want to go to the menu to upgrade andthen keep going. Oh and it would be nice if you could right click an upgrade to put in enough to upgrade it instead of having to click over and over.
Great job, you deserve more reviews!