Very nice, I like the idea of having to balance repairing the generators with fending off enemies but it felt a bit easy as holding down the mouse emits an endless stream of bullets that annihilate all enemies on screen in an instant and I could repair and exterminate simultaneously. Still it was fun because I never felt like I didn't have something to do. I really enjoyed the music too, it reminded me of the original Terminator movie. With some balancing this could be excessively fun.