This great sequel only adds to the greatness of the first game, making it unique, but still a sequel.
The game's "campaign" mode is very nice. It doesn't exactly follow the standard formula of Guitar Hero 1, but is still very staisfying. In each section there are four songs that you can play right off the bat, and after three of those four songs, the audience asks for you to play another song. This song is usually a really big song that a lot of people know, such as sweet child o' mine, and carry on my wayward son.
A new feature is the practice mode, where you choose a section of a song to practice by itself, helping you nail a song that you're having troubles with. The unlockable songs aren't all that great, seeing as half of the artists you probably have never heard of. The new characters are a nice adition, adding an 80's style rocker, a fat Kiss fan (type guy), and an afro dude. Now for the most important part: the songs. There is a great variety among them and they work very well.
If you liked Guitar hero, pick up guitar hero 2. If you didn't, try this game.