First of all, +1 to lorporlem's question: Does touching the border of the screen instantly kill you? If so, that should be explained in-game. The shooting and aiming feels smooth, and the effects look nice. Bonus points for the settings that get saved between sessions. The full screen toggle was on at first, but it still loaded as a window. Toggling it off and back on works, but you might want to know it does that since it only happens on the first launch.
Cheers :)