Activision's Call of Duty: Black Ops Zombies, the spin-off of Call of Duty: World at War's "Zombies" mode and sequel to Call of Duty: Zombies, is a first-person shooter zombie survival game where you shoot, stab, and bomb zombies on your iPhone.
Solo or multiplayer: Play by yourself or band with up to three teammates to return the undead to their rightful place in hell.
Various maps, characters, and difficulty levels: You'll never get bored, with all the different maps (featuring innumerable rooms to pass through), characters, and difficulty levels to choose from.
Satisfying gameplay: There's nothing more satisfying than slashing and shooting zombies as their blood and guts splatter everywhere. You'll also make a killing in currency, which you can use to unlock stuff in the game, and sometimes even power-ups, such as extra ammunition or double currency after each kill.
Crouching and sprinting: Walking and turning are fine, but you can do those in any ol' zombie shooter. Call of Duty: Black Ops Zombies also adds the ability to crouch and sprint, which can respectively help you hide and run fast when the undead are after you.
Voice chat: We love being able to chat with our friends in multiplayer mode. However, make sure to grant the game microphone access for voice chat to work.
Dead-Ops Arcade: As an added bonus, the game offers 50 levels of top-down arcade shooting: annihilate zombies, collect weapon upgrades, win score-increasing gems, and move on.
Tutorial: Helpful for first-time players, the in-game tutorial teaches you how to move your character, pick up weapons, and use them properly.
Shooting difficulties: Even with auto-aim, there were times where we found it difficult to shoot zombies by double tapping our screen. The inclusion of a fire button would certainly make things easier.
If killing zombies is your thing, you won't find a better first-person shooter than Call of Duty: Black Ops Zombies for iPhone. Just make sure you have the shooting part down before the hordes of zombies approach.