Really fun game with amazing visuals! The gameplay loop is really well designed with an amazing level-up mechanic.
Recently, I saw a lot of great games in Trijam(Like this one!) made in pico-8, which I think I should try for a bit! The game engine's theme is really good.
One small suggestion is for the power-up to have a shot pierce ability. I spammed z keys for a lot but I still couldn't clear the hoard of enemies. However, the amount of power-ups is already great!
Great job!