Much like Behind Enemy Lines, each mission features the player having control of a subset of commandos, though in some missions, the player begins with a few commandos to use, but can gain control of others through either contacting them somewhere in the mission's location, or rescuing them from imprisonment. The original six from the previous game are once more available for use, though some have a few notable improvements in how they can be used - the Green Beret can now climb telephone poles and traverse heir cables, can jump out of windows, and can carry small containers around; the Sniper can climb up telephone poles to use them as sniping positions; the Spy can now not only direct soldiers and lieutenants to look somewhere else, but can order soldiers and enemy staff to move somewhere else if disguised as an officer, while his syringe can now daze, knock out, or kill an enemy, depending on the number of doses they are given; the Diver now kills enemies by throwing knives at them, and now carries a grappling hook that can be used to traverse walls or set up a trip-wire to knock out enemies; the Driver can now set up traps, both lethal and non-lethal; and the Sapper can now use a mine detector to find buried mines and dis-arm them, as well as set-up mines to eliminate infantry and armoured vehicles. Along with these six, the players also gets control over three new members to use, including: the Thief, who is the most agile of the group, can climb in and out of windows and through small holes, hide in tight spaces, climb and traverse telephone poles and cables like the Green Beret, and unlock metal containers and some doors with his lockpicks; the Seductress, who acts like both the Spy and the Sniper, in that when disguised she can use her lipstick to distract enemy soldiers, but can't fool officers, and when not disguised, she can use a sniper rifle to take out enemies; and Whiskey, a dog who the commandos can use to trade items between them, as well as bark near enemies to distract them. In addition to the commandos, players also gain control of allied units, most of whom can be equipped with weapons and placed in four different combat stances, including firing out of windows and crouching down, and thus be used to combat enemies when needed.
Other new features include the player being able to explore interior locations and underwater locations, facing additional threats such as wild animals and Gestapo soldiers, the ability to salvage enemy weapons from their bodies to use when needed, such as rifles and sub-machine guns, the ability to use multiple cameras to survey a mission's location, the ability to hide bodies in bodies of water or amongst certain objects such as reeds, and the inclusion of new equipment - binoculars, flamethrowers, molotov cocktails, smoke grenades, rope ladders, gas grenades, canned food and first aid kits. While the various gameplay mechanics from Behind Enemy Lines are still used, such as line of sight, the ability to view enemy positions, and other enemy behaviours, such as investigating suspicious sounds or reacting to alarms, a number of areas received notable changes - All commandos can wear enemy soldier uniforms, though unlike the Spy, the effect last only for a limited time and as long as they stay out of close range of enemies; cars and lorries can be driven by all commandos, but armoured cars require the Driver, and Tanks need both him and the Sapper; the inventory system is a grid-like space, with objects taking up a certain number of spaces depending on their size; enemies now display a line of sight when detecting something in their view, which is orange for something that has caught their interest, blue if they spotted something suspicious, and red if they have seen a commando; and commandos will be shot on sight if they are discovered by the enemy, rather than captured, while alarms last for a while before they eventually end, although guards will investigate the area that triggered it.
Plot
In May 1941, commandos Paul Toledo and Natasha Nikochevski capture an Enigma machine and its codebook in a German submarine base at La Pallice in La Rochelle, France. While Natasha leaves the base, Toledo is ordered to stay behind with the Enigma to assist the other commandos (Jack O'Hara, Thomas Hancock, James Blackwood & René Duchamp) when they arrive at daybreak to rescue the crew of a Royal Navy submarine, the E-423, sheltered and under heavy guard in a submarine pen. They destroy the base's anti-aircraft guns and torpedo warehouse before escaping in the submarine.
While in the North Sea, the Royal Navy submarine is caught and forced to surface in the frigid waters after being depth charged by a German destroyer. The enigma machine is confiscated and the entire crew captured with the exception of Blackwood and Hancock, both of whom evaded capture. After rescuing the crew, the commandos proceed to recover the Enigma and disable the destroyer's main guns and boiler room. Under orders that the Enigma be hastily brought to England, O'Hara and Duchamp takeoff in a Fieseler Fi 156, while the rest escape in the submarine.
A year passes and the commandos are deployed to the Pacific Theatre. In Burma, they rescue a spiritual leader and assassinate a Japanese tyrant with the help of Gurkhas. On 17 June 1942, the commandos are sent to northern Thailand, where they rescue a Colonel Guinness, who in turn helps them destroy the bridge over the River Kwai by revealing its structural weakness. The bridge is blown up just as a train of the Imperial Japanese Army high command crosses it, plummeting into the river.
In July 1942, the commandos land on the strongly fortified Savo Island to disable the large artillery guns, before Operation Watchtower can commence. While on the island, they are assisted by a castaway named Wilson. After destroying the artillery and rescuing a downed American pilot, he returns the favour by piloting a Kawanishi H8K to help them escape the island, but not before telling them of a gold monkey statue which is symbolic to the Japanese. O'Hara steals it as a souvenir.
In Spring of 1944, the commandos are sent to Haiphong, Indochina, destroying the port's fuel depots and infiltrating the Japanese aircraft carrier Shinano. While out at sea, the commandos sabotage the rudder of every A6M Zero and report the carrier's position before escaping in two intact Zeroes. The Shinano is then bombed by American Vought F4U Corsairs.
Following their tour of duty in the Pacific, the commandos are recalled to the Western Front for the Normandy invasion. During the battle of Cherbourg, they rescue a wounded Private Smith, and with the help of American soldiers, successfully defend the town from waves of German infantry and Panzer III tanks. A few months later, Toledo is captured and taken to Colditz Castle where he is to be executed. The commandos save him and they help the prisoners of war housed there escape by disguising them in German uniform. While the prisoners escape, the commandos acquire top secret documents from three high-ranking German officers, revealing plans to devastate Paris with planted explosives before it is liberated.
In August 1944, the entire commando corps arrive in Paris and thwart plans to destroy much of the city, before leaving in an airship from top of the Eiffel Tower.
