Flying Hamster brags that it has almost 2 million players worldwide, and I don't see any reason to doubt that as the truth. After all, this game is about flying hamsters. It features 6 unique worlds, 35 different enemies, and 8 "freaky" weapons that you can find throughout each level. Additionally you can control the game in four different ways, allowing the player to use either on-screen controls or the accelerometer.
Flying Hamster and its HD version were both recently updated with support for 4-inch screens, iOS 7 game controllers, and Game Center. But the best part about the recent update is that both games are now completely free to download. Head over to the App Store and grab one (or both) of them now.