Unlike most games, and especially most FPSs, the different races in this game require the player to use different tactics. Players will have to use stealth to play humans, direct assaults to play CAT, and careful use of resources to play Alien. Each race will have its own powers and abilities, and will be able to use their own personal set of weapons and powerups suited to them.

Although Reprisal is set in a space station, it will have a large variety of environments; from narrow hallways to giant shuttle hangars, from alien zoos with hideous creatures breaking out of their cages to sterile reactor cores pulsing with radiation.

The story is played out in Joshua 20, a space station orbiting Pluto. This station contains the cryogenically preserved Cyborg Assault Tanks (CATs). CATs are machines that use human brains as their central computers; humans who have committed particularly violent offences are sentenced to become these killing machines. The CATs were used to put down uprisings in the outer colonies of the solar system, and are now being kept safe by the military and government until needed again.

A race of aliens, who resemble upright wolves or big cats, have decided to invade our solar system; their goal is to kill or drive out anyone living there and take the system for their own. The leader of the Aliens, known only as “The Prince” decides to take Joshua 20 first and turn the CATs against their owners, thereby reducing Alien casualties. The plan backfires, and the CATs go crazy, killing everything they encounter, human and alien. The Prince loses the loyalty of his troops, who turn on him.

As the game begins, the CATs (minus the player) have all gone on a killing rampage, the Prince must challenge each caste of his people to regain their loyalty, and the humans must survive the clash of powerful enemies to escape.