by FowThingies, published
A 3D labyrinth required a +/- 3mm marble.
It's a (not very hard) labyrinth with holes.
If a marble rolls in a hole, flip the labyrinth over :)
The mid part could be modified to create a different labyrinth.
Print all parts,
Put them together and play!
Edit part 2 to create a new kind of 'level'
(google sketchup file)