The game features a guitar-shaped controller (resembling a miniature Gibson SG) that the player uses to simulate playing rock music. The gameplay is similar to "GuitarFreaks", in that the player presses buttons on the guitar controller in time with musical notes that scroll on the game screen. The game features covers of 30 popular rock songs spanning five decades of rock, from the 1960s up through 2005, in addition to bonus tracks. "Guitar Hero" became a surprise hit, earning critical acclaim and winning many awards from major video game publications, and was considered one of the most influential games of its decade. The game's success launched the "Guitar Hero" franchise, which has earned more than $2 billion in sales, spawning several sequels, expansions, and other game-related products.