Maybe I'm reaching way too far but I've thought of things that I've seen on zombie shows (ie The Walking Dead, Zombieland) is there any changing of nature available to the player, such as boarding up windows or barricading doors? that would be a very realistic and easy add to the game. Add wood boards, nails and hand tools... allowing players to move furniture and appliances in a house. That would be really cool and wouldn't force players to be nomads ingame.