6GUN is a third person, tactical-action, modern combat game. In 6GUN you are the leader of an assault team in the highly classified GUNSLINGER program operated by the Special Operations Command (SOCOM). When diplomacy fails, and the US government needs a "deniable" military solution to its problems abroad, they call on the GUNSLINGERS.

The GUNSLINGER record of successful missions was recently shattered with a failed operation, and political pressures have relegated them to the second string of Special Operations while better known groups are assigned the best missions. GUNSLINGER Assault Team 2 is assigned a new leader (the player) and given equipment and personnel recovery missions in South America. In the course of the mission in the jungles of South America, the GUNSLINGERS discover surprisingly detailed information about Typhoon Class Ballistic Missile Submarines and the Soviet Northern Fleet in the possession of an international arms trafficker. Soon after, a Typhoon in the port of Primorsk for disarmament is attacked and boarded. A SOCOM operation to retake the sub ends in the detonation of a nuclear device and loss of an entire SEAL team, leaving the world in shock, and SOCOM in chaos.

As a result, the GUNSLINGERS are thrust back onto the center stage in the world of clandestine operations and begin to hunt those responsible for the attack in Primorsk. The hunt will take the player through 4 campaigns and at least 12 different levels, giving the avid gamer hours and hours of exciting combat gameplay! Gameplay will range from small unit combat, to close quarters battle (CQB), hostage rescue, demolitions, sniping from a helicopter gunship, High Altitude Low Opening (HALO) parachute insertions, and take the GUNSLINGERS around the world.