 The demo version of the game (available for download) has one scene not  available in any of the retail versions of the game. The scene is intended to  be an introduction narration by director David Cage. In it Cage walks into  Docs Diner just before the murder of John Winston and narrates to the player  what is about to happen and introduces the player the mechanics of the game.  This scene offers insight to players not familiar with the games world. In  the retail version of the game, this scene is missing and is instead replaced  by an interactive tutorial.