George Fan actually developed his tower-defense game by focusing on the plants first. After having finished Insaniquarium, he began toying around with a defense-oriented sequel to the game. "At the time I was also playing some tower defense mods in Warcraft III and thought 'What if I used plants as towers? Plants are great because you can give them lots of character, and no one expects them to move.' So out went the fish, in came the plants." By focusing on plants, Fan was initially afraid his game would be lost among the trees of another gaming sub-genre: gardening games. Explains Fan, "I thought, no way is anyone else going to make a game that features both plants zombies. And I was right."

The zombies, when they were included, would not be faceless hordes either. Fan's unique vision for his game boils down to a focus on gameplay; when creating the unique characters of the plants and zombies, he wanted to make things funny but also wanted to make sure that the game mechanics were sound. But there were some exceptions to this rule. He really wanted a zombie bobsled team included in the game, first appreciating how it would be funny and then deciding how it would work gameplay-wise. The zombie bobsled team became one of the more iconic (and original) characters from the game-not to mention one of the more difficult enemies to defeat. "It's nice to be able to sprinkle the humor in here and there. We had a fun time making this game, and hopefully it shows."

Ghostbird Software's team also chose a different way to depict the living dead. Instead of focusing on tower-defense and humorous characters, as Fan's team did, Lauren Jones and company focused on a unique game perspective: a mass zombie outbreak in an urban center. Instead of focusing on the intimate terror of zombies by getting you up close and personal, The Raging Dead creates a much more massive scale. Now, instead of dealing with two or three, you're dealing with hundreds. It's perhaps the best example of what a zombie outbreak might look like from a bird's eye view. Books like and some recent movies have illustrated the power and terror of zombies unleashed in a city center, but only The Raging Dead allows you to make the tough decisions on how to deal with it. Do you firebomb an area to box-in some zombies, whilst sacrificing some civilians? Or do you pick off zombies with smaller weapons and hope that it's enough to stem the tide? One of the most common themes in zombie movies is the moral ambiguity of what people must do to survive. The Raging Dead embodies that ideal.

Finally, ZombieSmash, due to be released to the App Store later this month, takes a more classic way to separate itself from other zombie apps: class. That is to say, Matthias Höchsmann and company are focusing on polishing the game; they're seeking a patent on their hilariously gory ragdoll physics engine, they've hired Chris Huelsbeck to ensure the game has a quality soundtrack, and they have a longer development cycle with a bigger budget than your typical indie title. While the subject matter is now commonplace on the iPhone, Gamedoctors aren't just jumping into the fray. They've taken the time to develop a quality game that just so happens to be a zombie game as well.

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