Cities can cause the player to be scared. I mean if you peek around a corner you can be grabbed by zombies easily, and also you have to be careful because you can easily be surrounded. Everyone knows The Walking Dead. Let's say you have this scene with the tank: http://seriable.com/wp-content/gallery/the-walking-dead-season-1-bts/episode-1-tank.jpg If you watch the episodes you can clearly see the advantages. You can't simply go one road filled with zombies. You have to try to go around it. Not just crawling past them. Or maybe you could go through a building, but who knows what is there. I know Real Virtuality 3 engine is very limited with buildings inside. But the outside part shouldnt be a problem. Maybe you can take Venezia: https://maps.google.be/maps?q=venetie&hl=nl&ie=UTF8&ll=45.436045,12.337775&spn=0.025747,0.066047&hnear=Veneti%C3%AB,+Veneto,+Itali%C3%AB&gl=be&t=m&z=15 Great town, small alleys, great view.