If you thought that the trend of zombie-themed video games couldn't get any stranger, Clickgamer and studio radiolaris have just released an iPhone game called Zombies vs Sheep, which pits the undead against every one's favorite woolly livestock.

The straightforward game has players holding off zombie hordes in order to protect their flock of sheep and help them move to safety. It makes use of a number of the iPhone's features for controlling the action - tap the screen to shoot, tilt the phone to move your sheep, and flick the phone to reload.

Zombies vs Sheep also sports an upgrade system where players can steadily improve their sheep as they progress, making them more resistant to attacks from the titular zombies, as well as from incoming bats and flaming skulls.

"The importance of protecting the sheep from invading armies of walking, crawling and flying undead is vastly underestimated by the current generation of political leaders," said musician Mario Dancso, who created the soundtrack for the game.

With the dial stuck on "wacky," Zombies vs Sheep includes 10 levels of difficulty, including three big boss battles. It's available for the iPhone and iPod Touch as of today for US$0.99 / C$1.10.