In Alien Syndrome, players take control of the game's strong and enigmatic heroine - Earth Command Trooper Aileen Harding - and battle a variety of fearsome aliens and colossal bosses. Gamers choose from a wide selection of character specialties and skills as they progress through an engrossing campaign, protected by many different types of armor and using a variety of melee and ranged weaponry. Players can improve their heroine's statistics and discover a huge number of powerful new abilities as they fight through infested spaceships and bizarre alien planets.