Treyarch Call of Duty games stand apart from Infinity Ward's own releases for many reasons, but the Black Ops dev's Zombies mode is one of the biggest. The World at War take on a walking dead-filled, wave-based survival mode was released in bite-sized form for iOS devices in November 2009 and now Activision is following it up with the release of Call of Duty: Black Ops Zombies.

The game hits the App Store today with a price of $6.99. Only one of the FPS maps is included, Kino Der Toten, but the app also includes Dead Ops Arcade, the unlockable, zombified dual-stick shooter from the 2010 console and PC game. Multiplayer is supported too, for up to four players, with a new voice chat feature also available. Dead Ops spans 50 levels, and the press release announcement mentions that "more features, upgrades and maps" are coming.

I always have a tough time playing FPS games on an iThing's touchscreen, but Dead Ops seems like a perfect fit for the mobile platform. Hopefully the promised expansions add more to that in addition to the expected console map releases.