Saturnalia is a survival horror game set in the fictional town of Gravoi on the island of Sardinia. It takes place at night with a permanent fog and hues of purple, adding to the eerie atmosphere. The story follows four characters - Anita the geologist, Paul the photojournalist, Sergio the drug addict, and Claudia - each with their own secrets and objectives.
The gameplay is centered around survival and exploration, as the players must navigate the cramped environment, avoiding an unkillable creature that roams the town. Players can sprint, hide, or distract the creature using sound or firecrackers. The game features a roguelike design with customizable characters and a large number of items to gather and use.
The game takes place in a randomized structure, with key locations such as a church, castle, villa, and town hall. Players must work together to solve puzzles and complete missions, which can be done by specific characters due to their abilities. The gameplay is challenging, with optional permadeath and limited stamina.
The game features a unique puzzle-solving mechanic, where clues are stored on a separate screen, showing connections between characters, items, and missions. Prominent items include matches to light the environment, bonfires to mark paths, and firecrackers to lure away the monster.