I can't say I really knew what I was doing most of the time, but it was pretty fun! Got 200. I think it would be good to make the complexity ramp up more slowly (i.e. introducing the mechanics and enemies each at a time so that it isn't too overwhelming right at the start of a run).
Also, the aiming center seems to be fixed at a point at the bottom right of the screen rather than at the player, which made shooting a bit more difficult.