To remain undetected, the player can perform techniques which make use of both Solid Snake's abilities and the environment, such as crawling under objects, using boxes as cover, ducking or hiding around walls, and making noise to distract enemies. An on-screen radar provides the player with the location of nearby enemies and their field of vision. Snake can also make use of many items and gadgets, such as infra-red goggles and a cardboard box disguise. The emphasis on stealth promotes a less violent form of gameplay, as fights against large groups of enemies will often result in severe damage to Snake.
Despite the switch to 3D, the game is still played primarily from an overhead perspective similar to the original 2D Metal Gear games. However, the camera angle will change during certain situations, such as a corner view when Snake flattens himself to a wall next to an open space, or into first-person when crawling under tight spaces or using certain items such as the binoculars or a sniper rifle. The player can also use the first-person view while remaining idle to look around Snake's surroundings or see what's ahead of him.
Progress is punctuated by cutscenes and codec, as well as encounters with bosses. To progress, players must discover the weaknesses of each boss and defeat them. Play controls and strategies can also be accessed via the Codec radio, where advice is delivered from Snake's support team; for example, the support team may chastise Snake for not saving his progress often enough, or explain his combat moves in terms of which buttons to press on the gamepad. The Codec is also used to provide exposition on the game's backstory.
In addition to the main story, there's also a VR training mode in which the player can test out their sneaking skills in a series of artificially constructed environments. This mode is divided into three main categories (practice, time attack, and gun shooting), each consisting of ten stages. After completing all 30 stages, a survival mission is unlocked in which the player must sneak their way through ten consecutive stages under a seven-minute limit.
Characters
The protagonist is Solid Snake, a legendary infiltrator and saboteur. During the mission, Snake receives support and advice via codec radio. Colonel Roy Campbell, Solid Snake's former commanding officer, supports Snake with information and tactics. While he initially keeps some secrets from Snake, he gradually reveals them. He is joined by Naomi Hunter, who gives medical advice; Nastasha Romanenko, who provides item and weapon tips; Master Miller, a former drill instructor and survival coach; and Mei Ling, who invented the soliton radar system used in the mission and is also in charge of mission data; the player can call her to save the game.
The main antagonist of the game is Liquid Snake, leader of a now-terrorist splinter cell of the organization FOXHOUND, and genetic counterpart to Solid Snake. An elite special forces unit, FOXHOUND contains experts specializing in different tasks. Members are Revolver Ocelot, a Western-style gunslinger and expert interrogator whose weapon of choice is the Colt Single Action Army; Sniper Wolf, a preternatural sniper; Vulcan Raven, a hulking Alaskan shaman armed with an M61 Vulcan torn from a downed F-16; Psycho Mantis, a psychic profiler and psychokinesis expert; and Decoy Octopus, a master of disguise.
Other characters include Meryl Silverburgh, Colonel Campbell's niece and a rookie soldier stationed in Shadow Moses who did not join the revolt; Dr. Hal Emmerich, the lead developer of Metal Gear REX; and the "Ninja", a mysterious cybernetically enhanced agent who is neither an ally nor an enemy of Snake but does oppose FOXHOUND.
Plot
The year is 2005, six years after the downfall of Zanzibarland. A renegade genetically-enhanced special forces unit, FOXHOUND, has seized a remote island in Alaska's Fox Archipelago codenamed "Shadow Moses", the site of a nuclear weapons disposal facility. FOXHOUND threatens to use the nuclear-capable mecha, Metal Gear REX, against the US government if they do not receive the remains of Big Boss and the ransom of $1 billion within 24 hours. Solid Snake is forced out of retirement by Colonel Roy Campbell to infiltrate the island and neutralize the threat.
Snake enters the facility via an air vent and locates the first hostage, DARPA Chief Donald Anderson. Anderson reveals that Metal Gear REX can be deactivated with a secret detonation override code, but dies of a heart attack. Colonel Campbell's niece Meryl Silverburgh, held hostage in a neighboring cell, helps Snake escape. Snake locates another hostage, ArmsTech president Kenneth Baker, but is confronted by FOXHOUND member Revolver Ocelot. Their gunfight is interrupted by a mysterious cyborg ninja who cuts off Ocelot's right hand. Baker briefs Snake on the Metal Gear project and advises him to contact Meryl, whom he gave a PAL card that might prevent the launch, but he too dies of a sudden heart attack.
Over Codec, Meryl agrees to meet in the warhead disposal area on the condition that Snake contacts Metal Gear's designer, Dr. Hal "Otacon" Emmerich. En route, Snake receives an anonymous codec call warning him of a tank ambush. Snake fends off the attack from Vulcan Raven and proceeds to the rendezvous, where he locates Otacon. The ninja reappears, and Snake realizes it is his former ally Gray Fox, believed dead. Otacon agrees to aid Snake remotely using special camouflage to procure information and supplies.
Snake meets Meryl and receives the PAL card. As they head for the underground base, Meryl is possessed by psychic Psycho Mantis and pulls her gun on Snake. He disarms her and defeats Mantis, who informs Snake that he has "a large place" in her heart. After they reach the underground passageway, Sniper Wolf ambushes them, wounds Meryl, and captures Snake. Liquid confirms Snake's suspicion that they are twin brothers. After being tortured by Ocelot, Snake is confused to discover Anderson's body in his cell, seemingly dead for days. He escapes, makes his way up the communications tower, and fends off a helicopter attack from Liquid. As he emerges onto a snowfield, he is confronted again by Sniper Wolf. He kills her, devastating Otacon, who was infatuated with her.
