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.Achievements
Accomplish the indicated achievement to get the corresponding number of Gamerscore points:
- Environmental Awareness (5 points): Kill a zombie using an environmental hazard in any game mode.
- Gas Powered (5 points): Complete an entire arena, getting every kill with the Chainsaw.
- Gun Shop (5 points): Kill at least one zombie with each weapon type in any game mode.
- More the Merrier (10 points): Kill 10 or more zombies at the same time in any game mode.
- Socialite (5 points): Play in an online multiplayer game.
- Tour of the City (15 points): Complete each arena at least once in the same game in any game mode.
- Can't Touch This (20 points): Rack up a 100x multiplier in any game mode.
- Friends in Low Places (20 points): Save 25 survivors in any game mode.
- Interior Decorator (20 points): Kill 25 zombies in any game mode using environmental hazards.
- A Week To Live (25 points): Complete 7 days in any game mode without dying.
- Hotter Than Hell (25 points): Complete the final day of the "7 Days of Hell" unlockable mode.
- Anniversary of the dead (45 points): Complete the Final Day, in either Single or Multiplayer, and finish the game.