HorrorGPT by ちゅーりん

HorrorGPT by ちゅーりん is a Japanese-made Chrome extension that turns an ordinary ChatGPT session into an escape-the-room horror story game. It was created by the developer ちゅーりん and released in 2023 for the Japanese-speaking audience. Rather than being a standalone app, it is a prompt-and-interface layer that sits on top of ChatGPT and delivers a haunted escape scenario you play through by typing commands.

The extension supplies story prompts, a horror-styled presentation, background music, sound effects, and voice clips so a plain text conversation feels like a suspenseful game. Because the difficulty and story settings are driven by the prompt itself, players can rewrite the setup text before sending it to change the scenario, ramp the challenge up or down, or strip out audio and background-color effects entirely if they prefer a plain chat.

The developer publishes the underlying prompt code openly on GitHub, and the base prompt is also documented on the creator's note page. This means players can download the prompts and register their own favorite scenarios, custom BGM, or voice assets. As a free, fun-focused extension it is aimed at casual players who want a Japanese-language horror interactive fiction experience without installing a full-size game.