Yeah, if you play for a long time, running the screen and the network at the same time will kill your battery.

Yes, and I have also noticed that it eats up a lot of memory.. You will need a good app killer and use it frequently

Has anyone noticed a significant drop in battery life after leaving Words With Friends open on your phone (even after the phone automatically locks)? I'm pretty sure it's this game, but I haven't confirmed it yet.