How much of a game is required?  Can it be one single level?  Does the art and audio have to be polished or original works?

equivalent of one playable level and featuring at least one mechanic with clearly defined start and end points. The art and audio do not have to be polished. However, you must have the right to use all assets as well as the right to grant permission to the Dallas Game Producers and the National Videogame Museum to showcase your submission.