Yuji Horii, the designer of Dragon Quest and the 1983 adventure The Portopia Serial Murder Case, released a free browser mystery game on 11 October, and says he made it with generative AI in about 30 minutes. The game is called Komiya in the Interrogation Room (取調室の小宮, Torishirabeshitsu no Komiya), a rough translation of its Japanese title. Horii announced it on X, as reported by Denfaminicogamer and Gogo Tsuushin.
Interrogating a former locksmith
The player questions Komiya, a 72-year-old former locksmith suspected of breaking into a pawnshop safe, and has to find where his statements contradict the evidence. Komiya has two meters, agitation and resistance, which shift with each question and each exposed lie. A rattled suspect is easier to break; if resistance reaches 100, he stops talking. We have not played the game. This description comes from Denfaminicogamer’s report, and we have not checked which languages the game supports.
What Horii said about making it
Horii contrasted the project with Portopia, for which he wrote the story, drew the art and did all the programming himself on PC. Now, he wrote, “just by giving instructions to an AI, one person can make a decent game”, adding that he was genuinely surprised. Denfaminicogamer quotes the Japanese original. In the coverage we could read, Horii does not name the AI tool he used, but the game link in Denfaminicogamer’s report points to a shared app page on claude.ai, Anthropic’s AI assistant service. Gogo Tsuushin reports that the release drew a large response on social media, with players and developers surprised at how fast it was made.
A different use of AI from the 2023 Portopia preview
In April 2023 Square Enix released SQUARE ENIX AI Tech Preview: THE PORTOPIA SERIAL MURDER CASE free on Steam. It used natural language processing so players could type or speak free-form instructions to the detective’s assistant, and Square Enix said it had removed the generative-reply feature because the AI might produce unethical replies. That preview put a language model inside a classic game as the conversation layer. Komiya uses AI as the development tool, directed by one designer to produce a complete, if tiny, game.
A 30-minute browser game is a sketch, not a product, and Horii does not present it as more. What stands out is who is sketching: a designer whose career began with doing every job on a project himself, now publicly testing an AI-directed prototype in a genre built on dialogue, contradiction and deduction.
Disclosure: GameTales uses Claude Code, an Anthropic product, for research assistance. Anthropic had no involvement in this article.