I've managed to kill about 500 of the zombies living in the mall, and there are still loads more, especially in back rooms and hallways. All of my weapons broke, so I gave up on trying to use one and killed most of them with my bare hands. Need to watch out for crawlers though. I got scratched by one and thought I was infected, but it was just a fake infection (curse you hypochondriac)! Another thing to be careful of is the roof, there isn't anything to stop you from falling. The "second floor" is actually 3 floors up in most places, this includes the roof. I've found a trowel, spade, multiple saws and hammers, but I've yet to find a single axe or any type of sand or gravel bag... With all the corpses lying around you'd think there would be a few. Some of the bodies do have pistols though. I think the biggest problem I ran into was food, I couldn't get to anything in the food court due to the massive amounts of zombies there. I guess in that regard the zombies are really the major issue. I had to filter all of them out into the open and slowly pick them off one at a time (took me at least 10 minutes at one point). If you go to the mall you can expect a lot of the rooms and stores to be filled with zombies.