Expanding the length of a game is not impossible, even for a short action game. While no one expects to play an FPS campaign that lasts longer than 10 hours, some first person titles, like the Call of Duty series and Valve"s Orange Box offer extensive multiplayer options that allow the product to last for dozens or even hundreds of hours. But for every one of these games, there are five other games that do not last beyond a single play-through in which such options are nonexistent.

What could possibly be done to improve the value of a game?