Early handheld games utilized very simple mechanisms to interact with players, often limited to illuminated buttons and sound effects. Notable early handheld games included the Mattel Auto Race (1976) and Mattel Electronic Football (1977) which featured very simple red-LED displays; gameplay involved the player pressing buttons to move his car or quarterback icon (represented by a bright dot) to avoid obstacles (represented by less bright dots). In 1978 the Milton Bradley Company entered the handheld market with Simon, a simple color-and-sound-matching game. Simon had no dedicated display, but featured four colored, lighted buttons; the original version was large enough to be used as a tabletop game or a handheld; later versions became increasingly smaller. The same year, Parker Brothers a