I really like what you've done. There are a few quality of life issues I think would vastly improve the experience.
Screen options are limited to full screen or window, but there is no changing the actual size that I saw. With such a low resolution style game (which I like by the way) I feel like being able to play in a smaller window would make sense.
Pressing Escape ends the game. This is unfortunate, as I always assume escape will bring up the menu. Even knowing this does not help as pressing Escape is almost an instinctual habit. I'm sure I'm not the only one who feels this way.