Beleaguered Castle is a solitarie game. Considering he (Colter Stevens) was all alone in the source code (or at least his physical body is), they must have chosen this name. One unique thing about this particular type of solitaire game is that there isn’t much room to maneuver which can also be said of him in the source code. See Wiki entry for it: http://en.wikipedia.org/wiki/Bel… Also, here is another interesting description about the game itself, especially the words – erode the wall – break down that wall between reality and virtual reality (as it goes in the movie). So pretty ingenious to choose that name. The objective of Beleaguered Castle solitaire is to erode the “wall” stacks on the sides of the layout by placing their contents in the suit stacks in the middle. (Beleaguered Castle can be considered “FreeCell without free cells”, but card stacks do not need to have alternating colors and the aces are already removed to compensate (partially) for the lack.) Source: http://www