Most cases I'm familiar with are from old games with an attract mode or games made by people who grew up with those games and imitated that behavior. Attract m

Most cases I'm familiar with are from old games with an attract mode or games made by people who grew up with those games and imitated that behavior. Attract mode serves two practical purposes: drawing customer interest in stores and preventing screen burn in by varying the content on the display periodically. Basically, it's a built-in trailer plus screensaver -- someone just turns on the game in a store and the demo runs itself unless you press a button to start playing.