Very unique, looks nice and square too, a characteristic that's often overlooked although at times just as difficult as any mortise and tenon. Is it a type of marble maze game or simply a visual craft? Either way, very nice work.
Yes it is a marble maze as long as the marble is smaller than 3/8. I use a steel bearing for weight. It can be a seaked unit or have openings in the case. I have not decided.
Update! Working in the garage this weekend. I am hoping to finish three different obscured mazes in Maple Burl, Walnut Burl, and Cherry Burl for an upcoming project! I am excited! Should look awesome as a viewable maze / labyrinth.