Ready for a marble tour?? Your objective is to maneuver the marble from one corner of the box to the diagonal corner of the box. You can see the marble at various points through the holes in the case. There are some marbles in fixed positions that will likely confuse your progress a bit but if you are clever they can also act as guideposts. A puzzle of dexterity to maneuver the marble and logic to determine the path. Measures about 5 3/4" sq x 1" deep