They're aliens. If they're hell-bent on bringing the electric death, that's kind of the idea. If you've not caught up with them in military terms, it's a good idea to keep them so busy fighting each other that they pay no attention to the man offering them hefty bribes.
Windowed mode only puts you in a window if you select a resolution less than your desktop size and uncheck the Fullscreen box, otherwise it does a full-size window, which actually runs just as well as fullscreen.
Also, if this community is dead then I'm one of them really fast zombies so like, watch out.