The player can select from four difficulty levels: Walk on the Beach, Combat Op, Suicide Mission, and the hardest difficulty, FUBAR, which is only unlocked after completing the game on Suicide Mission.[1] Various new weapons and equipment become available as the game progresses, some dropped by downed enemies.[2] These include several different rifles, handguns, and machine guns.[3] Some offer alternate firing modes, like attaching a suppressor or using a telescopic sight.[4] Players can also acquire and make use of grenade launchers, hand grenades, and rocket launchers.[5] However, the player can only carry two weapons at a time.[6] Supply caches can be found in different parts of the game, allowing the player to refill their ammo and grenades.[7] Whenever the player successfully shoots an enemy in the head, the game enters a slow-motion mode for a short period of time. The player can also defeat enemies at close range via melee combat. Dying enemies can be executed, which grants the player additional ammo.[8] Hiding behind cover can provide protection and prevents the player from being shot, as well as providing opportunities to blindfire or lean out to shoot enemies.[9]
As a third-person shooter with an emphasis on squad-based tactics, players can issue commands to Sergeant Lugo and Lieutenant Adams, who accompany the player for most of the game. Available commands include focusing fire on one particular target and ordering medical attention for an injured squad member. Adams can defeat enemies by using heavy gadgets or throwing grenades, while Lugo provides sniping assistance.[5] Environmental hazards like sandstorms occasionally occur, drastically reducing the player's vision and visibility.[10] Sand becomes a key gameplay mechanic and players can manipulate it at scripted moments in the game, such as triggering a sand avalanche to bury enemies alive.[11][12] When a grenade explodes on sand, dust clouds that can blind enemies are formed.[5] Sand sometimes opens up new paths to allow players to progress.[13]
The player needs to make moral decisions at certain points during the game,[14] including making choices that can determine the fate of both soldiers and civilians. These decisions affect the relationship between Walker and his squadmates, and will cause them to react differently.[15] The game incorporates several subtle effects to visualize the lead character's increasing mental and physical distress; alongside the degradation of their combat uniforms, Walker suffers visual and auditory hallucinations later in the game, and his executions of enemies become more violent. The orders and shouts to his team become increasingly angry and ragged in contrast to his stern but collected orders at the outset. His kill confirmations of enemies corrupts from professional in the beginning to psychotic.[16] Similarly, loading screens initially display helpful gameplay hints for the player, but as the game progresses, the text becomes increasingly hostile towards Walker's actions, and sometimes breaks the fourth wall by addressing the player directly.[17]
