Unpleasant Horse, the first game from PopCap's new label 4th and Battery, is apparently quite edgy. It was initially rejected by Apple, since the game involves ponies being thrown into meatgrinders and all, but now Unpleasant Horse is available on the App Store. The best news? The game is free of charge.
Unpleasant Horse is a one button jumpy affair, with a bit of a learning curve, but it's worth it for the money. Given that it's totally free.