seems little repetative. maybe add different enemies and environments and guns and bullets and so on and it is a good bullet-hell game or something. Good job for a jam though!
I got out of bounds by flying forwards of the screen and to the left or right.
like pdil said, maybe add space-key as shooting button or just make it autoshoot constantly as I was just helding the button down all time.
You can add little variety to the bullet shoot sound by lowering the pitch randomly by small degree.