Atom

Atom is an original, educational game that came in cartridge form from Radio Shack/Tandy. It teaches you the beginning of the periodic table, while you build the elements (and learning how many electrons each has). You have to pick up electrons, and them shoot them to hit the "energy level ring" dots (the innermost circle of dots, near the atomic nucleus). If you are successful, you have created the next element, and it will show the periodic table, and which elements you have succeeded at (highlighted by orange on dark red text).