This is awesome!
One of my favorite games so far! The game being the controls is a very fun idea!I don't remember the level number, but the level with the cannon where you scrolled side to side and used the joy stick knob to go up and down might be my favorite of the ones I played. Felt very good to time the shot to hit just right.
I really liked the screen effect as well! I wanted to get something similar for my game, but I don't know enough about Godot shaders yet and didn't give myself enough time to learn. But you nailed it!
Amazing job!