my gpu is burning up :0
i like the idea but it gets a bit monotonous, perhaps you can add events that force the player to change their priorities so that they don't just go in a circle feeding everyone. i'm not sure what energy does, but i like that idea of multiple resources. as for the framerate problems when there are lots of zombies, i think you can use gpu instancing to make lots of zombies with better performance, but i don't know how exactly to do that.
neat concept