Cute art! The music was fitting too. The idea of using the missed shots from your enemies as YOUR ammo is fantastic. As for feedback, I think having some kind of penalty in points/health for letting enemies get to the bottom of the screen would be helpful because I found staying to one side and ONLY killing those enemies was very effective at surviving and getting a highscore:)
Oh, and I noticed you also worked on art for another game I saw in a different jam I was in recently! Great work there too!