Gamespot writes: "No doubt as a result of the brand's meteoric rise to fame, Guitar Hero has evolved into a bit of a video-game industry octopus. Bear with us here. While the core gameplay mechanics in Guitar Hero haven't changed much between iterations, the financial juggernaut unleashed by its upward spiral in popularity has necessitated its evolution from an amorphous blob into something sprouting several distinctive sub-franchise limbs. First, there's the guitar-only brand that launched the game, and the format we last saw with Guitar Hero III: Legends of Rock. Then there's the mobile version, Guitar Hero: On Tour, which has been specifically designed for the Nintendo DS handheld and takes advantage of a GBA slot peripheral. Next up is the multiplayer-focused band experience of Guitar Hero: World Tour, which launched late last year."