Birds are known for two things: singing and pooping. Turd Birds for iOS explores the dark side (rather, the chalky-white side) of avian life with an endless running game that's probably better described as an endless pooper. For a game that's all about excrement, Turd Birds surprisingly isn't caca. It doesn't advance the case for video games as an art form, but you will enjoy bombing the obnoxious humans scuttling below you.
In an interesting twist which may be of benefit to iPhone games, GridBlock feels less like a video game and more like a board game. And we don't mean your regular checkers or chess, but more along the lines of something slightly more physical, like a Perfection or an Operation.