 The popularity of the Guitar Hero series has led to the development of several commercial and independent clones. Besides Harmonix 'Rock Band series, Konami released Rock Revolution in 2008 which features drums and guitar (the game does not include vocals) similar to Guitar Hero World Tour. PopStar Guitar for the PlayStation 2 and Wii systems, developed by XS Games, features gameplay similar to the Guitar Hero series, but features pop music, as opposed to rock and metal. Digital Praise released a Christian rock-themed guitar-based game called Guitar Praise also in 2008. Guitar Rising, to be published for personal computers by Game Tank by 2009, is based on using a real guitar in order to perfect one's skills. We Rock: Drum King is a game promoted by Rolling Stone for the Wii that uses two Wii remotes as virtual drumsticks. Frets on Fire is an open-source clone of Guitar Hero for personal computers that features freely available independent songs and allows users to create their own note tracks. Other games based on Guitar Hero include Battle of the Bands and Ultimate Band. Guitar Hero has also influenced other games outside of the music game genre. Tim Schafer credits Harmonix and the first Guitar Hero game to help establish his pitching of his heavy metal-inspired game, Brütal Legend, due to the increase in popularity of metal music from the success of Guitar Hero. Guitar controllers have been repurposed as controls for an independently developed platform game, Fret Nice. Rock of the Dead for the Wii is based on combining the aspects of The Typing of the Dead with using a Guitar Hero guitar controller to fend off zombies. A PlayStation Home themed space based on Guitar Hero, called "Guitar Hero: Backstage", was released on March 26, 2009 in North Americas version, and includes a "Simon says" -like minigame called "Guitar Hero-Master of Rock", themed objects, and videos for the user.
