Metal Gear Solid 2: Sons of Liberty is a sequel to the espionage action game Metal Gear Solid . In the story, two years after the Shadow Moses incident, Solid Snake - now working for a freelance organization known as Philanthropy - infiltrates the oil tanker U.S.S. Discovery, investigating the development of a new Metal Gear-type weapon.
A confrontation with a Russian military group and an old acquaintance from Snake's past adventure leads to a massive detonation, after which Snake is presumed dead. Fast-forward to 2009: the player takes control of Raiden, a rookie agent operating under the order of the Colonel, who appears to be a member of a reformed Foxhound unit.
The initial assignment is to infiltrate the offshore clean-up facility Big Shell and rescue the President of the United States of America, who was kidnapped by members of a terrorist organization known as Sons of Liberty. However, things become increasingly complicated as almost everyone Raiden communicates with appears to have a hidden agenda, making it hard to tell a friend from foe...
The gameplay remains similar to its predecessor, with the player having to sneak past guards, outsmart them using various gadgets, and defeat tricky boss enemies. New weapons can be picked up throughout the game, including some old favorites like the FAMAS and Socom, as well as new additions such as the AK-47.
Martial arts combos can be used to disable guards, and the protagonist can also crawl through small spaces, peek around corners, and perform acrobatic leaps to get away. The cardboard box is back and can once again be used for hiding. Gadgets like the sneak suit, mine detector, thermal goggles, and others can be found along the way.
The radar from the original game is still present, alerting the player to guards' positions and showing their field of view. However, if an alarm sounds, the radar is disabled, and the hero has to escape quickly. In some situations, it's necessary to enable the radar before it becomes possible to use it.
The game is heavy on codec conversations and cutscenes, with all cutscenes using the in-game 3D engine and motion captured animations for character movements.