According to ESRB, this game contains: Cartoon Violence
Parents will be hard pressed to find objectionable content in this game. The only concern is if the game might be too hard for a younger child. I know kids nowadays are quite savvy with gaming, but some of these puzzles are fairly challenging.
Wii fans owe it to themselves to give Zak & Wiki a try. It truly is an enjoyable game, which provides something different from the norm that can appeal both to the casual and hardcore crowds.
Point-and-click adventure fans have likely heard about this game, and wonder if it would remind them of the classics. I don't have extensive experience with those kinds of games, but from my limited exposure to the original Monkey Island or Broken Sword, I would say the similarities are on the surface only.
Deaf and Hard of Hearing gamers will find this game suitable, as all spoken words are actually written text. Characters "speak" by voicing a wordless exclamation unique to each character, while the dialog appears written on the screen. This handles all the exposition and instructional information, so these gamers will be good to go.