Deep Fighter, a Criterion Studios developed game, puts you in control of a variety of submarines designed for combat. It is considered a first person shooter, despite being vehicular based, drawing inspiration from Wing Commander for the PC. Like its predecessor, you are able to move freely in any direction as the entirety of the game takes place underwater. The game features 24 missions across two discs, and like Wing Commander, makes liberal use of Full Motion Video.
The player is put in the role of a new graduated private (callsign MORAY 2) from the Academy, a training institute for submarine pilots. The Academy is a part of a wholly underwater civilization which is under siege by enemy threats (the Shadowkin) and a seemingly natural disintegration of the environment. Ultimately, the goal is to aid the civilization develop a mother ship and then protect it in order to transport the entire society from these threats.
As noted, the core mechanic of the game is full 3D motion in a fluid, allowing for control much like Wing Commander and Descent. Throughout the course of the game, you pilot a series of 5 subs and an ROV (Remotely Operated Vehicle) that are suited for a variety of tasks. One of the key gameplay elements is combat, which operates much like dogfights in a flight or space sim, often engaging numerous enemies with the aid of teammates. Battles are broken up by pathfinding, item collection, and puzzle solving, all of which are designed specifically around the idea of full 3D motion.