If you have seen Dawn of the Dead, you already have a good idea on how to solve most of the puzzles. But here's some extra tips anyway:
1. To lock up the mall to keep zombies from getting in, you need to park the trucks over the entrances. Get the key from the office on the 2nd floor and go to the 4th floor where the keys to the trucks are kept.
2. To keep the dead zombies from coming to un-life, lock them up in the freezer in the basement.
3. Before you can go play in the basement, you need a source of light. Get the fuses and gloves from the 3rd floor and go to it!
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