Enemy Zero is one of the horror titles by Warp, closely connected to D (and its sequel D2 for Dreamcast). It also features the same heroine as in D series.
The story follows Laura, who awakens from a state of suspended animation on board her spaceship, Aki. She soon discovers that a hostile alien life form has infiltrated the vessel, and it's up to her to reestablish contact with her crewmates, navigate through the ship's maze-like corridors, and defend herself against the invisible aliens.
The gameplay combines puzzle-solving adventure and shooter elements. When exploring rooms, players enter first-person perspective mode, allowing them to examine objects, solve puzzles, and take in their surroundings. In ship corridors, the game shifts to first-person shooter mode, where the player must rely on sound cues to detect invisible enemies. The intensity of the sounds indicates the distance between the player and the enemy.