Story
Metal Gear games are notorious for their convoluted, intricate and deep narrative that mixes serious themes such as war and free will, with supernatural elements. MGS4 takes place years after the events of MGS2 as Solid Snake who is rapidly aging since he is a clone is attempting to stop his rival Liquid Snake (who has possessed Revolver Ocelot through a transplanted arm) from taking over the world with nano-machine controlled soldiers.
Traditionally the story in MGS games have been told through "CODEC" conversations where two people spend copious amounts of time talking to one another with animated avatars. In response to criticism the traditional CODEC conversations have been replaced by full real-time cinematics. Some of the story presentation is presented while playing the game, most of the cinematics are non-interactive.
Gameplay
MGS4 introduces several refinements and changes to the traditional Metal Gear Solid gameplay, while retaining many of the core elements that make the series. The biggest change comes in the gameplay perspective which now defaults to a regular third-person view from behind Snake's back. Other camera angles are available including an over-the-shoulder view, the birds-eye angle, and even a first person view.
Snake has more tools and weapons at his disposal including the OctoCamo which is a cameleon-like suit that automatically changes colors and patterns to match his surrounding. The Solid Eye and Metal Gear MK.II are two other tools that Snake can use to help his progress.
