The mobile game was developed by Limbic Software and released July 21, 2011 for Apple’s iOS, September 19, 2013 for Android on the Google Play Store, and October 8, 2013 on Amazon.

The player can complete objectives to earn military ranks (which adds a reward multiplier all future missions) and collect coins for various purposes.

During game play the player can toggle night vision between white and black hot modes, which affects the coloration of civilians and zombies.

The smaller zombies appear humanoid, are fragile and shamble quickly, whereas the larger ones crawl slowly, are less common but also highly resilient.

Bunker Charlie 1 is a simple terrain containing hills, Bakersfield is an industrial power station with a train running through it every few minutes, Pleasant Acres is a housing tract, and The Lockdown is a large prison complex surrounded by several walls.