This is a game where you stack blocks of the color shown on the die on top of a semi-circular block without collapsing them! I have kept this at home for many years. Dimensions: Semi-circular block: Height approx. 3cm, Diameter approx. 6cm White block: Diameter approx. 1.7cm Yellow block: Height approx. 1cm, Diameter approx. 1.7cm Orange block: Height approx. 1.5cm, Diameter approx. 1.7cm Green block: Height approx. 1cm, Diameter approx. 2.5cm Blue block: Diameter approx. 2.3cm Red block: Height approx. 2.5cm, Diameter approx. 2.5cm Die: Diameter approx. 1.5cm It's mini-sized, so it's easy to carry around. How about it for a brain workout?