Set of 19 pieces includes 2-piece paddlewheel launcher, 2 launch balls, 5 X blocks, 1 ramp, 1 goal cup, 2-piece hoop target, set of decorative stickers, and set of 5 challenge cards. Early introduction to concepts such as speed, angles, and distances. Totally kid-powered launcher: no batteries, springs, or rubber bands! Encourages trial and error approach to problem solving through game-like challenges. Hoop target, when constructed, stands approximately 12" tall.