The first entry in our Gadget Freak Design contest is in, and it’s a doozy: Matthew Katzenstein created this sweet 3x3x3 RGB LED matrix, controlled by an Arduino Diecimila, that plays a game of blue-vs-red 3-dimensional tic-tac-toe. The video, above, is lengthy and quite detailed. You can watch it work starting at 5:30 (it should automatically start there if you click the embedded player above); the whole video can be seen here.