The art & game over screen are cool, really liked them but I've been getting into some weird bug (?). I constantly get a game over screen although I'm not doing anything wrong (at least from my perspective). Shooting somewhere on "gray area" - suddenly game over. Shooting cacti - all of a sudden game over.
A quick tips that I can give you on Godot side, try playing around in Project settings -> Window -> Stretch (Mode & Aspect). It should make your game more responsive and avoid those gray areas (unless it was a design decision). You probably didn't have enough time but adding some SFX would really benefit you and those are easy to do.
There is definitely more to learn and its awesome to see how much progress you made with Godot during this jam. Keep up the good work.