I've also just heard that the game eats batteries for breakfast! While I've been playing it a lot, I usually do so plugged into my computer and failed to notice this.
Here is my question to my very own technical expert, Mr. Zhang.
Would simply bright graphics drain a lot more power than darker graphics or would this possibly indicate a lot of heavy processing? It's a turn-based game so it isn't like it needs to update the screen constantly like some 3D action arcade game. Or could extra heavy battery drain really just be a matter of inefficient coding?