Guitar Hero is a hell of an addicting game. I got it Saturday, and I've had guitar solos going through my head since then.
Graphics: 8/10. They are definitely simply and only "fair" compared to games out now. They still look good, but as I would think, they probably thought it was more important to get the music and songs on level first.
Sound: 9.5/10. The singers are NOT the real thing ( for some of the songs I knwo for sure in a video you can unlock ) but they sound damn close! Especially Bark at the Moon and Iron Man ( besides the beginning "I am iron man". ) Franz Ferdinand is also done pretty well.
Control: 9/10. The game takes you from noob to pro pretty much. You start out with the first three buttons on easy, first four on medium, and hard and expert introduces the fifth. I simply can not play with the five buttons; way too hard, my fingers get mixed around, even if there is a little notch on the yellow key, just like there is on the F and J buttons on a keyboard.
Fun: 9.5/10 Over 45 songs, multiplayer, plenty of unlockables including 2 characters ( one is definitely cool, find out if you get the game ), a lot of songs, guitar skins, guitars, and the-making-of videos. This is one addicting game, and I can see myself easily playing this for at least another 6 months to a year, no doubt.