In Nemesis, you will be plunged into the core of sci-fi survival horror, filled with terror and suspense. A soldier fires blindly down a corridor, attempting to halt the alien invasion. A scientist hurriedly works to find a solution in his makeshift laboratory. A traitor seizes the last escape pod at the last second. The intruders aboard the ship not only react to the noise you create but also evolve as time goes by. The longer the game lasts, the more powerful they become.

Throughout the game, you control one of the crew members, each possessing a unique set of skills, a personal deck of cards, and individual starting equipment. These characters cater to all your essential sci-fi horror requirements. For instance, the scientist excels at working with computers and research but struggles in combat, whereas the soldier excels in battle situations.

Nemesis is a semi-cooperative game where you and your crewmates must survive on a ship overrun with hostile organisms. To win the game, you must complete one of the two objectives dealt to you at the beginning of the game and return to Earth unscathed. Numerous obstacles will impede your progress: swarms of Intruders (the name given to the alien organisms by the ship's AI), the ship's deteriorating condition, hidden agendas of your fellow players, and sometimes just plain bad luck.