Successfully complete the indicated task to unlock the corresponding mode:
- 7 Days Of Hell: Successfully complete Day 55. In this mode, you must survive seven very long levels with different graphics effect.
- All Weapons: Successfully complete Day 55. In this mode, you can use any weapon with infinite ammunition.
- Blackout: Successfully complete Day 55. In this mode, your view is limited to a small circle around your character. The circle expands when more players are near. Also, radioactive zombies become very visible.
- Chainsaw Only: Successfully complete a level using only the chainsaw. You cannot have any environmental or Zombie Bait. In this mode, you are limited to the chainsaw and Zombie Bait.
- Hardcore: Survive seven days with no deaths. In this mode, you only have one life and cannot gain any more.
- Turbo: Get a 100x multiplier. In this mode, everything moves faster.
Stand next to survivors and throw a teddy bear in a safe direction to distract the zombies.Trophies
Successfully complete one of the following tasks to get a trophy:
- A Week to Live (Silver): Complete 7 days in any game mode without dying.
- Anniversary of the Dead (Gold): Complete the Final Day, in either Single or Multiplayer, and finish the game.
- Can't Touch This (Bronze): Rack up a lOOx multiplier in any game mode.
- Environmental Awareness (Bronze): Kill a zombie using an environmental hazard in any game mode.
- Friends in Low Places (Silver): Save 25 survivors in any game mode.
- Gas Powered (Bronze): Complete an entire arena, getting every kill with the Chainsaw.
- Gun Shop (Bronze): Kill at least one zombie with each weapon type in any game mode.
- Hotter than Hell (Silver): Complete the final day of the "7 Days of Hell" unlockable mode.
- Interior Decorator (Bronze): Kill 25 zombies in any game mode using environmental hazards.
- More the Merrier (Bronze): Kill 10 or more zombies at the same time in any game mode.
- Socialite (Bronze): Play in an online multiplayer game.
- Tour of the City (Bronze): Complete each arena at least once in the same game in any game mode.