From Wikipedia: Steel Diver consists of 3 main modes: Missions, Periscope Strike, and Steel Commander. Missions is further broken down into 2 modes: Campaign and Time Trials. The main gameplay occurs during Campaign. In Campaign, the player uses sliders and dials on the touchscreen to manoeuver a submarine through side-scrolling levels displayed on the top screen, sinking enemy submarines, battleships and avoiding naval mines and depth charges as required. There are seven missions available, playable with different subs and difficulty modes, which usually involve goals such as eliminating enemy fleets or infiltrating enemy bases by reaching the goal in a time limit. Time Trials features the same gameplay style and controls, however the levels are shorter and are not connected to the story, instead being solely to achieve a fast time through a complex path. Periscope Strike mode is played after every successful mission or can also be played separately, or as part of Steel Commander. This mode sees the player moving the system to rotate a periscope to fire torpedoes at enemy ships. Steel Commander is playable against the CPU or a human opponent via Download Play. It is a strategy game in which the two players command a fleet of battleships and submarines and try to sink each other's fleet.[