The Manhole, being a kind of "Myst for kids", is a nice way to get young people into computer games. No blood, no violence, just a surreal world waiting to be explored.
[url=http://www.gog.com/en/gamecard/the_manhole_masterpiece_edition]The Manhole: Masterpiece Edition is an exploration-oriented game and the first title made by Cyan Worlds, who later on created the famous Myst series. Created with the younger audience in mind, there is no way to actually "lose" in this game. The main protagonist is a little boy who lifts a manhole cover, only to uncover a magical beanstalk leading to wacky locations both above and below. The game has no ending as such - it's all about exploring and having fun, as discovering its wacky world's every secret becomes a goal in its own right.