The player may choose from four different timelines. Starting in the early 1980s limits the player to
Permit, or early -class submarines, but the Soviets have weak
sonar, whereas starting in the late 1980s allows the player to use the improved
Los Angeles class and even the newer subs. Weapons improve accordingly, with
Tomahawk missiles and improved
Mark 48 torpedoes included in later timelines but the Soviets begin deploying
nuclear-powered aircraft carriers and much better
anti-submarine warfare ships. The goal of the game is always consistent: inflicting as much damage as possible on the Soviets in the Norwegian Sea, thus allowing safe passage to supply
convoys coming from America and preventing amphibious forces from conquering Norway and Iceland. In order to make contact with enemy forces, the player must navigate the sub in a map of the North Sea, depending on his sub's sensors as well as allied aircraft, satellites and
SOSUS arrays to detect the Soviet forces. Success or failure of the missions impacts the progress of the war depicted by shifts in the front line on a simple map of Europe. If the player fails in a mission then Soviet forces capture more territory, but if the player succeeds then
NATO is able to resist the Soviet attacks. In the course of the campaign the player can gain rank and possibly earn medals as well. In the end of the war, a final score is calculated and the player is awarded a post-war rank if NATO wins the war; this rank can vary from
commander to
admiral depending on how successful they have been in their missions. A poor performance in the game, particularly in the final mission, means that the Soviets win the war and the player ends up with the rank of
Tovarishch (comrade), becoming a political prisoner in a communist-ruled America. ==Reception==