1. A gravity-based marble run game to enhance critical thinking and have your child constantly challenging themselves by undertaking harder and harder levels. Great for developing logical reasoning, spatial reasoning, and planning skills, this game will have the whole family joining in on the fun and working together to get through all 60 challenges. Promising review: "Bought it for my 6-year-old nephew, and he loved it! The game is set up so that my nephew could figure it out intuitively with minimal guidance. It introduces children to fundamental concepts of physics and problem-solving mechanics in a very natural way." - Seoung Kim Get it from Amazon for $24.72.