Found the third level to be super hard, but it's a neat idea. Bullet economy seems to wave from being super strict to being able to just blast away without worrying about needing to gather more bullets. Looks/sounds amazing, shooting and movement were also good. I would be curious to see these mechanics put into a wave based survival mode in a larger map. Running around and taking cover whilst you also need to stay outside to gather more ammo seems like a neat combo.
Great jam game, can easily see this being fleshed out with more mechanics and enemies to make it really awesome ;)