Fun game!
I managed to completed it after a few tries, but it took a while until I learned the correct tactic for beating it.
Initially I was a bit confused as to how to shoot, but your instructions helped out.
Maybe it would be fun to add some coins or other things that incentivize the player to move further down, since it feels like otherwise the best strategy is to just fly as high as possible all the time.
Nice job on the art and the game design execution overall!