Unlock the following modes by performing the corresponding tasks:
MODE - HOW TO UNLOCK
7 Days Of Hell - Beat Day 55. In this mode will be seven very long levels.
All Weapons - Beat Day 55. In this mode you will be able to use all weapons and have inifinite ammo.
Blackout - Beat Day 55. In this mode your view is shrunken to a small circle around your character. Radioactive zombies will become more visible.
Chainsaw Mode - Beat a level using only the chainsaw, and without any environmental or Zombie Bait. In this mode you will be limited to the chainsaw and Zombie Bait.
Hardcore Mode - Survive seven days without dying. In this mode you will only have one life.
Turbo - Get a 100x multiplier. In this mode everything will move faster.
To distract a zombie from survivors, throw a teddy bear in a direction away from the survivors.
Can't Touch This - Rack up a lOOx multiplier in any game mode.
Environmental Awareness - Kill a zombie using an environmental hazard in any game mode.
Gas Powered - Complete an entire arena, getting every kill with the Chainsaw.
Gun Shop - Kill at least one zombie with each weapon type in any game mode.
Interior Decorator - Kill 25 zombies in any game mode using environmental hazards.
More the Merrier - Kill 10 or more zombies at the same time in any game mode.
Socialite - Play in an online multiplayer game.
Tour of the City - Complete each arena at least once in the same game in any game mode.
A Week to Live - Complete 7 days in any game mode without dying.
Friends in Low Places - Save 25 survivors in any game mode.
Hotter than Hell - Complete the final day of the "7 Days of Hell" unlockable mode.
Anniversary of the Dead - Complete the Final Day, in either Single or Multiplayer, and finish the game.