This is a combination of manual dexterity and problem solving. Manual dexterity is necessary to keep the marble on the track. But problem solving is also required to figure out the proper way to turn and rotate the globe to move from one obstacle to another.
The Perplexus comes in three flavors: Rookie Perplexus, Original Perplexus, and Perplexus Epic, which is featured here.
We have the "Original Perplexus" and have found it to be a great conversation piece; when we have visitors in our home, often the Perplexus ends up getting passed around the room repeatedly, as people take turns trying to get through the three dimensional labyrinth.