The ammo mechanic is pretty interesting and fits the theme well. Maybe if the balls bounced off the walls, I could plan my shots so that the ammo bounces right back into me. I like the quick arcade-y feel of the game too. Sometimes I would run into an issue where the enemies would spawn on top of me and I'd immediately take damage, so that hindered gameplay a bit. Overall good concept! Mashing up a sports and shooter game definitely has some potential.