AEGIS: Guardian of the Fleet is a simulation of the U.S. Navy's Ticonderoga class guided missile cruiser. It features over 100 missions in seven battle sets and a training area, as well as a detailed "Warbook" full of interactive weapons/platform information.

The main focus of the game is the realistic simulation of the war ship. It is set in modern times which means there are a lot of technical systems to the player's disposal. The most important ones are the tracking systems (e.g. radar, active or passive sonar) and weapon systems (e.g. torpedo, rockets or anti-aircraft). Every station offers many settings or actions to consider. These can be reached from the bridge where the player can switch between the stations by clicking on the corresponding monitor. There is also a tactical map which can be used to start attacks. Typical mission goals are destroying enemy units (ground targets, submarines, ships or aircraft), escorting friendly units or recon missions.