Playing the ENI Puzzle is very simple. Everyone who sees ENI for the first time can easily start playing without any instruction. The ENI PUZZLE is designed to enhance problem solving and dexterity. A workout for the mind while using hand and motor skills. The Eni Puzzle has 3 different sizes and 2 different color schemes. The larger size is equipt with braille. The medium size (called the "mini" is the hardest, ast it has the most pieces in each column. There is also a miniature keychain, dubbed the "keychain" , which dresses up iphones and other accessories.