With over 50 million sold, ThinkFun is the world’s leading manufacturer of brain games and mind challenging puzzles. Gravity Maze is a combination logic game, marble run, and STEM toy that’s one of the best gifts you can buy for boys and girls age 8 and up It contains 60 challenges from beginner to expert, a game grid, 9 towers, 1 target piece, and 3 marbles. Easy to learn with a clear, high quality instruction manual You can start playing and solving right away.