Dreamkiller is a dark fantasy first-person shooter where the player takes on the role of Alice Drake, a psychologist with the ability to enter the minds of her patients to fight the monsters appearing in their dreams.

The action takes place in dreams, so locations are all based on a person's personal phobia: a zoo infested with spiders, an arctic area full of sunken ships, a factory-like place filled with living machinery, a hospital, a twisted forest, and more.

Each level is preceded by a comic-like cutscene, and is usually culminated with a battle against a boss, which is an enforced version of an enemy previously encountered.

Alice Drake is a very special psychologist, who enters her patients' dreams and battles their fears, which take forms of insane monsters.

In order to put an end to insanity it brought to the real world, she enters the Dream Devourer's domain and slays it.