Metal Gear Solid 2 Substance is an action-packed game that follows the story of Solid Snake as he infiltrates a highly advanced facility known as Big Shell. The main antagonist, Liquid Ocelot, has taken control of the facility and is threatening to launch a nuclear missile at the city of London. With the help of his allies, Snake must navigate through the treacherous terrain of Big Shell to stop Liquid's plans and uncover the truth behind his identity.
Gameplay in Metal Gear Solid 2 Substance involves stealth, strategy, and action elements. Players control Snake as he moves through the facility, avoiding enemies and completing objectives while trying not to be detected. The game features a variety of gadgets and equipment that Snake can use to aid him on his mission, such as his trusty sword and grappling hook. The game also has a complex character customization system that allows players to upgrade Snake's abilities and unlock new weapons.