I’ve been playing Urban Dead for a month now. It’s a fun game. I have three characters: a private (zombie killer), a zombie (human killer), and a scientist (zombie studier).
Some of the players have gone on strike because the zombies don’t have that many cool powers. Humans can get special “Zombie Killer” skills, they can use items, etc. Zombies can (1) bite and (2) claw.
So, my idea is that, if there are ten or more zombies in a given area (be it inside a building or outside), no human can leave for another area (i.e. go inside or to a new square) unless they kill a zombie in that area. Picture a swarm of zombies blocking all your exits: you can only escape by punching a hole out.
You would still need a fearsome number of zombies to make this into an actual game-shifting effect (where you surround areas and invade buildings to make them human-free), but it might make Malton feel more like it’s owned by the zombies. (It would also give zombies an advantage in being outside buildings, to counter the humans’ advantages inside buildings.)