I'd find this game hard to be on the bad list. It has strict rules about being family friendly. Though some people dont always obey it so parents should watch their kids and make sure.
It's a great way to encourage creativity in a child. They can build their own levels for others to play, and in the recent release of Little Big Planet 2, they can create and entire story line to play.
I'm 26 (and a 1/2....

) so I'm getting accustom to saying 27. I play the game like a little kid. One of my mottos is that I refuse to grow up cause all that's left is growing old. Besides, Jesus said that we must have the heart of a child if we are to inherit the kingdom of God.