Shellshock: Nam '67 is a 2004 third-person shooter video game developed by Guerrilla Games and published by Eidos Interactive for Microsoft Windows, PlayStation 2, and Xbox. The game leans atmospherically into a gritty, war-torn aesthetic with a grainy visual filter simulates the look of ’60s war photography and films, reinforcing the harshness and grim reality of combat.

The player experiences combat from a third-person perspective, with the character visible on screen as they navigate the jungles, villages, and tunnels of Vietnam. The game emphasizes a sense of realism rooted in the era, rather than carrying an over-sized arsenal, the player is limited to one heavy weapon, a sidearm (or two sidearms), and collection of grenades. Weapons are historically modeled: from Vietnam-era rifles to mounted machine guns, which the player can even pick up dropped weapons from defeated enemies, such as AK-47s.

Movement and combat reflect gritty, close-quarters warfare. The player can crouch, go prone, and lean to take cover behind natural features like rocks, trees, and terrain contours, which promotes a more tactical approach rather than a run-and-gun style. The environment is not just decoration: using foliage and terrain strategically allows the player to mask their presence and choose safer lines of engagement, evoking the tension and uncertainty of real jungle combat.

A notable gameplay mechanic is the “shellshock” meter, a system reflecting the psychological and physical toll of combat. As the player sustains damage, the meter fills, making them more vulnerable and less resilient, which is essentially punishing reckless behavior and encouraging a more cautious, deliberate playstyle. In other to recover, the players must find moments of reprieve, hide, so the shellshock meter will be able to drop.

Damage modeling in the game is quite detailed. Rather than enemies always dying instantly, they may suffer different “hit response states,” from light wounds to more severe damage, including dismemberment, depending on weapon type and hit accuracy. This layered damage system adds weight to firefights and underscores the brutality of the conflict. When enemies die, they often drop their weapons, which player can then scavenge and use. Addition to large-scale battles, it includes stealth-oriented missions, where players might be tasked with infiltration, assassination, or rescuing prisoners, operating more covertly rather than engaging in all-out firefights. There are also set-piece moments: for instance, the player may man a helicopter gun position, adding variety to the pacing of combat.

Between missions, there is a base camp phase which functions as a kind of hub. Here, the player can interact with other soldiers and officers, trade or acquire items, and ready for the next mission. These interludes provide role-playing elements, giving the player a chance to manage resources, gain intelligence, or customize their approach to future operations.

Missions are structured to reflect different phases of the protagonist’s “tour of duty.” As the player advances, they may be promoted into Special Forces, such as new mission types and tactical challenges. The variety of mission design, ranging from open battlefield engagements to tight stealth assignments, helps maintain tension and reflects the unpredictable nature of the Vietnam War. The combat system would then reward players a tactical thinking and caution. Due limited ammo, realistic weapon behavior, and the threat of shellshock, players are encouraged to use the environment, change their position, and make deliberate decisions about engagements. There is no single “correct” way to complete many encounters, whether to rush in with firepower or pick off enemies from covered angles is often left to the player’s judgment.

The game starts in January 1967 in Saigon, South Vietnam. A CH-47 Chinook containing Caleb "Cal" Walker, the game's protagonist, and other G.I.s, lands at Tan Son Nhut Air Base in southern Saigon. Walker, along with his squad mate, Private "Psycho" Kowalski, are chosen by Colonel Salter, the CO, to participate in an air assault on a Viet Cong encampment within Kon Tum province. Walker and Kowalski are put under the command of Lieutenant O'Brien along with another G.I. nicknamed "Short Timer". As Caleb and his squad proceed through the area, a friendly fire incident, involving flawed mortar coordinates, forces another G.I. named Tompkins, to join the squad. Along with the help of a special operations squad made up of Sergeant Ramirez, "Tick Tock" and "Eyeball", they help Walker and the others clear out the VC encampment. The encampment is soon after converted to a fire base, which serves as a headquarters for Walker and his unit.