Tweet Defense HD, the iPad version of the popular iPhone game, looks as fun as the original. The only difference is that now the zombie-filled tower defence game is made specifically for the iPad. And a bit pricier.
Keep in mind that you don't actually need a Twitter account to play the game. But if you do have one, then you can use a "Booster" function that lets you use follower and tweet counts to slaughter more of the undead.
The game is $10 and available in the App Store now. [iTunes]