I had like 2 cops around in the same house, protecting eachother. They were completely sorrounded by zombies, as the zombies had slipped past them. But then, even thou they survived greatly, one of them just ran down into the south end FILLED with zombies and died, and as the other didnt have friends to cover him, he got killed too...
*Comment to the game itself*
I'de say, what about trying to add like the special infected from l4d or smth like that? Or just some special zombies atleast? nd then there is settings for how high % they come when infected.