Harpoon II is a simulation of modern-era naval combat. A variety of ships such as surface and sub, as well as missile weapons and aircraft must be tracked and accounted for when engaging in battles. It is a single player game, and takes place in real-time (though you can set the clock ratio to suit your needs and even pause the game).

Rather than being a straight Cold War-style U.S.S.R. vs the USA game, Harpoon II's scenarios are mostly based on third-world encounters, such as USA vs North Korea, or Peru vs Ecuador, etc. Sometimes the sheer volume of detail can be overwhelming, this game is not recommended for casual wargamers.

You take charge of a naval force composed of either few small ships armed with only cannons and light rockets/missiles, or an entire carrier strike force with it's own air force and long-range cruise missiles.