One of the prettiest game in the jam! I'm happy to see that we both have a similar settings. Thought we'd get some point for originality but nope.
Jokes aside, the game is cool, the game's palette makes everything really visible, it's not too hard nor easy, the tank is a bit of a pain to dodge though if had to criticize something about it.
Also I don't really see your interpretation of the theme ? Aside from the limited color palette. Gameplay wise it plays and feels like a regular shmup... a good one but still.
Anyhow, good work nonetheless!