With 62, 208 (Square) or 165,888 (Star) different possible puzzles in a 6X6 grid, these games pose a different challenge every time. And every single one has at least one solution! Roll the dice, place the blockers, then race your opponent to fill out the gird using the various shaped pieces.  Also great played as solitaire against the clock.  Genius Star is the more challenging of the two, made even more difficult by using the "Golden Star" variant.  Great for adults & kids 6+.  Promotes problem solving and motor manipulation skill training.