The simple color-matching gameplay principles will test the younger kids and the complicated puzzles and tricky control will challenge their parents. Even if you never explore beyond the initial 100 levels you are guaranteed to get your moneys worth.
The real issue is whether or not players will be able to accept the outdated visuals, discernable camera problems, and heavy-set control scheme. For those of you that can handle it then Mojo! is one heck of a little puzzle game.