Full Spectrum Warrior is a squad-based game in which the player issues commands to two fireteams, Alpha and Bravo. Each fireteam has a Team Leader equipped with an M4 carbine. The Team Leaders also carry the Global Positioning System, which can be used to locate mission objectives and enemy locations, and a radio for communication with headquarters. The second team member is the Automatic Rifleman, equipped with an M249 Squad Automatic Weapon, used to lay suppressive fire on the enemy and assigned to take command if the team leader is shot. The third team member is the Grenadier, equipped with an M4 with an M203 grenade launcher attachment. The last team member is the Rifleman, equipped with a M4 carbine. If a member of the team is wounded, another member of the team will carry them. Lieutenant Phillips is the team commander and the player will usually find him with the CASEVACs, which are healing and ammunition points. Each fireteam has a limited amount of fragmentation and smoke grenades, in addition to the M203 grenades. Occasionally throughout the game, there will be a third asset designated as Charlie Team, ranging from anti-armor engineers to US Army Rangers.
Throughout the game, the player does not directly control any of the fireteam members; instead, orders are given using a cursor that projects onto the environment, letting the player tell his/her soldiers to hold a position and set a specific zone to cover with fire. It is also possible to order them to lay down suppressive fire on a given zone to cover the second squad's movement, or to reduce incoming fire.
Gameplay revolves around the concept of fire and movement, with one team providing suppressive fire while the other moves. The basic gameplay mechanics remain the same for the retail version of Full Spectrum Warrior, which was released on the Xbox, PlayStation 2 and Windows platforms. The retail version places much more emphasis on aesthetics; it possesses substantially improved graphics and sound. Cut scenes and voice acting are also characteristics that distinguish the retail version from the military version. The original military version of the game can also be unlocked within the retail Xbox version, by inputting the code HA2P1PY9TUR5TLE on the code input screen.
Source: Wikipedia, "Full Spectrum Warrior," available under the CC-BY-SA License.