Mediaeval Quest is based on Adventure for the Atari 2600. Released Christmas 1979, Warren Robinette’s Adventure was one of the earliest graphical adventure games (it very likely was the first). Mediaeval Quest is not a direct port; it deviates from Adventure in significant ways, but is also very similar in others. And, like Adventure, it contains a so-called Easter egg, a hidden feature that is revealed after completing an esoteric series of actions in the game. Thanks to Donnie Russel, the autor, for the news.