Richard Gain is not the only one making puzzles on Shapeways. We also are lucky to have Oskar van Deventer. He makes a lot of great puzzles in a lot of varieties and you can see them all in his Shop. My favorite puzzle by far is Plugged Dice. Basically it is a cube where you can insert the plugs to make up the points on the dice. Oskar says of it, "This is quite a puzzle as each plug can be inserted in many ways, but the whole fits only in one way." It sounds fiendishly difficult. Check out the video of the puzzle below.