As a photojournalist, Frank gets rewarded with Prestige points for documenting the horrors that surround him. As he accumulates Prestige by taking pictures, Frank can augment his arsenal of attacks with hilarious feats like zombie crowd surfing. He can also earn Prestige by saving random people he finds cowering among the brain-craving monsters ... even though he's under no obligation to do so.
A helpful security guard named Otis will occasionally radio Frank over his walkie-talkie with news of people in need of assistance. Otis keeps a watchful eye on a bank of security monitors within the bowels of the mall and serves Frank his objectives. These objectives are arranged in what Capcom calls the Case System, which works a little like a quest log, storing Frank's individual leads and collected clues. If Frank can solve all of the cases, the origin of the zombie nightmare will be revealed ... or you can just hide him in a closet until the helicopter arrives to save the day (though that would earn you the least interesting ending).