I think you've got a solid base here. However, the game feels too easy (i stopped after reaching 2000+ points with full health), and after reaching about 800 points i stopped trying to avoid incoming damage and just focused on getting points & powerups. I think if you use more objects at a time/different objects with varying damage instead of just increasing their speed, you could have a better difficulty curve. Would also have loved to have waves push XR-77 to the left and right which could really make the gameplay more dynamic. Of course its a jam game so there is never enough time to do everything, and i think this could be a really fun mobile game if it's fleshed out ;)