OMG.... Bug alert.... well kinda a cheat, on the main menu if you watch the zombies kill some of the humans and then collect the money you start off with a little more.... I might be wrong, can someone verify?
I think that a news reporter is the evil mastermind. Think about it. She always knows just how many people were killed and/or infected, and she knows if there were any survivors. She survived the first zombie takeover, and then repopulated the world. But as soon as the world got re-populated, another zombie outbreak starts, and guess who is there to cover the story.
Kind of wish i could just buy epic weapon designs instead of only unlocking one after every mission. It would make the game more fun and less disappointing when i dont get to the chest at the end. But other than that 4/5 good game.