Little Nightmares II is a puzzle-platformer and survival horror game in which players control Mono, a young boy navigating a nightmarish world warped by the transmission of a distant Signal Tower. Gameplay combines environmental puzzle-solving with stealth and light combat, as Mono and his AI companion Six work together to evade grotesque enemies and traverse dangerous environments. The game is a prequel to the original Little Nightmares and features collectible items that unlock additional story content.

Mono, a boy wearing a paper bag over his head, awakens alone in a dark forest haunted by recurring dreams of a hallway and a door marked with an eye. After discovering Six imprisoned in a remote shack, the two children escape her captor and drift toward the Pale City, a fog-shrouded urban ruin littered with old television sets. Drawn by some connection between the televisions and his strange dreams, Mono pushes deeper into the city alongside Six, passing through a schoolhouse ruled by monstrous figures and a hospital crawling with unsettling patients. Ahead of them looms the Signal Tower, the source of a pervasive broadcast that has twisted the city and its inhabitants into something terrible.