688(I) offers single play in three categories: Training, Single Mission and Campaign (15 missions linked together, almost creating a story). There is also a multiplayer function with the option to play with or against other players on selected missions. The game includes a mission editor which can be used to create new missions or edit existing ones (to add ease or difficulty).
688(I) comes with a 286 page instruction manual which covers everything from loading the game to detailed information on real ships and weapons. There is a tutorial divided into two parts (beginner and advanced).
Ship's Stations include Ship Control, Sonar (including broadband, narrowband, DEMON, Active, and Active Intercept), Radar, Radio/ESM, Target Motion Analysis, Fire Control, Periscope, Ship's Information, Jane's Online (information on other ships in the game), Navigation, 3-D Object View, and 3-D Control Room (a memory eating option which allows you to walk from station to station in a virtual submarine)
