According to ESRB, this game contains: Lyrics
Parents don't have much to be concerned about. None of the songs contain any explicit lyrics, and none of the visual content is inappropriate for teenagers.
Fans of the original Guitar Hero will certainly enjoy the sequel, although the song list is perhaps not as broadly appealing.
HDTV owners will appreciate the addition of widescreen and progressive scan modes.
Deaf and Hard of Hearing gamers could play the game in principle by following the notes that appear on screen, but since the fun comes from hearing what is being played, I wouldn't recommend it.