Ring World is a maze ball. The yellow ball turns around within the black ring. When the ball and the ring are correctly aligned, then the ring+ball together can be split in half, and the treasure inside the ball can be removed.
Watch the YouTube video
Read at the Shapeways Forum
Read more at the Non-Twisty Puzzles Forum
Please order a 3D-printed do-it-yourself puzzle kit from Shapeways at this page (check with Oskar about colors), or contact Oskar
directly if you are interested in obtaining a fully colored and assembled sample of this puzzle.