You're the commander of a nuclear submarine class "Polaris". Your mission is to defend our country from attack by enemies.
You have to face one of three enemy submarines and five bombers in the squad. You have to destroy bombers by firing rockets. After the destruction of the bomber squadron, you must be willing to dive bomber dropping torpedoes that plunge into the depths and then move horizontally. After destroying it, you have to go through the canal, avoiding or torpedoing minutes to reach the next level. Sometimes an enemy destroyer will move around the screen and drop depth charges.