Dottori-Kun, a 1991 demake of Sega's 1979 maze game Head-On, was created not to be played, but rather as a legal loophole around Japan's Electrical Appliance and Material Control Law which claimed that all arcade machines must contain a game when sold. Dottori-Kun allowed Sega to sell generic Astro City arcade machines which the arcade owner could swap the contents of at their leisure, and included test features to ensure the machine worked properly before installing a proper game. The game did not support coin insertion, and therefore was not a viable option for arcades even if an owner believed there was an audience for its simplistic gameplay and graphics, leading to the board being scrapped most of the time.