Complete the indicated ask to unlock the corresponding modes. Note: All modes are unlocked after Day 55 is completed.

Chainsaw Only: Complete a level with all kills done with the chainsaw. You cannot have any environmental or Zombie Bait. In this mode you are limited to the chainsaw and Zombie Bait.
All Weapons: Unknown. In this mode you can use any weapon with unlimited ammunition. Press Left or Right to scroll through the weapons.
Blackout: Unknown. 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.
Hardcore: Survive seven days with no deaths. In this mode you only have one life and cannot gain any more.
7 Days Of Hell: Unknown. This mode consists of seven very long levels with a different graphics effect.
Turbo: Get a 100x multiplier. In this mode everything moves faster.