Criss Cross Cube - Don´t screw your brain over! You have 21 places for your 13 screws - sound easy, or not? But whenever you place on screw, you will shut one, or more of your options.Criss Cross Cube - Don´t screw your brain over! You have 21 places for your 13 screws - sound easy, or not? But whenever you place on screw, you will shut one, or more of your options.