There is occasionaly a bug when you finish a stage where the "Stage complete" screen stays there forever, you can still play the background game though, this consisted even if you started a different playthrough. Also, i think there are some slight loading screen issues, the music seems to speed up massively then.
Anyway, pretty fun game, i like the music. The weapons are cool and well implemented, which is kinda the core gameplay
If i want to critique i'd say the starting ships are quite unbalanced. I don't even understand how you're supposed to do anything with the "rammer". Would also like some more visually interesting ship designs, for both playable and enemy ships.
Nitpicky stuff: Runes is a bit of a weird term to use for a ship-based game. Also the shop offers stuff you can't afford to buy, although i don't know if that's on purpose or not. Sometimes it also only offers very cheap weapons when you have lots of cash.