Plugged Dice

Plugged Dice   (idea by Fred Horn)

Plugged Dice is one of those gems of a puzzle. It has a clear theme - dice. It has the perfect shape - 3" cube. It has an obvious goal - fill the red cube with the eight white plugs. Normally these plugs would be straight cylinders, but not with Oskar. They all are curved! Each plug can fit in any hole many different ways but there is only one way they all fit together in an interlocking sequence.

Plugged Dice

Rota Cubes

Rota Cubes (Oskar and Bram Cohen)

RotaCubes is a twisty puzzle formed by three cubes in a tetrahedral cage. The corners of the tetrahedron are open allowing the three cubes to settle neatly into to three of the corners. The sides of the cage are red, green, yellow and black. One of the cubes has sides of red and yellow and black. Another cube is colored yellow , green and black. The third cube is colored red, green and black. Any one of the three internal cubes can roll over the other two into the fourth unoccupied corner of the cage. The goal of the puzzle is to thoroughly mix up the cubes and then attempt to roll the cubes until they are aligned with matching colors on the three sides that expose themselves in their corner.

Trapped Marble

Trapped Marble (Oskar and Bram Cohen)

Trapped Marble is a puzzle with a marble trapped inside a frame. The object is to free the marble. The marble is (conveniently) halved in a peculiar way which helps in its removal. There, I've already given you a hint. This puzzle is now being made by Hanayama in metal.

GeorgeMiller made much more puzzles for Oskar. See below on his website for more