Kumitantei: Old-School Slaughter is a detective game with a card-based combat system and visual novel elements, where the player investigates murders and survives among a group of trapped characters. The gameplay combines dialogue, clue collection, and turn-based encounters, where the outcome depends on the correct deck and understanding of the situation. Deduction through a deck Progress is based on analyzing what's happening and choosing actions at key moments. Cards represent skills, arguments, and actions used in conflicts and investigations. Mistakes lead to losses, while correct combinations reveal new details, allowing for a deeper understanding of the situation and closer to solving the mystery. The plot develops through interactions with characters and the gradual revelation of their motives. Each character behaves differently, and their choices influence the scenes available and the outcome of events. The player must decide who to trust, what steps to take, and how to proceed to avoid becoming the next victim. Features of the game Episodic structure with a gradual unfolding of the story. The visual style is in the spirit of late eighties anime. An alternative version of the historical period of Japan. The atmosphere of a tense, confined space.