It's a 3-D puzzle and a building set in one! This follow-up to the best-selling, award-winning Mental Blox game is specially made for younger players. Kids as young as 4 will love solving 28 puzzle challenges by stacking the colorful, engaging blocks into the right combinations. The perfect way to encourage early development of critical thinking and logic skills. Includes Activity Cards to guide the play! Tray measures 6 1/4 'L x 6 1/4 'H; cubes measure 2'L x 2'H.