Dragon Quest creator Yuji Horii has released a free, browser-based mystery game that he says took approximately 30 minutes to create using artificial intelligence, offering a glimpse of how generative AI can help experienced designers turn ideas into playable prototypes.
Titled Interrogation Room Komiya, the game was shared by Horii on October 11. In his post on X, Horii compared the experiment with creating The Portopia Serial Murder Case in 1983, when he handled the story, artwork and programming himself. He said AI now allows someone who cannot draw or program to create a reasonably good game by giving instructions to the technology. In Interrogation Room Komiya, players act as a police officer questioning Komiya, a 72-year-old former locksmith suspected of robbing a pawnshop safe. Players select questions and present evidence to expose contradictions in his statements. They must also manage the suspect’s agitation and resistance: push too hard, and he may refuse to cooperate.
その昔、PCで『ポートピア連続殺人事件』を作った時は、自分で物語を考え、絵も描いて、プログラムもして、ひとりでゲームを作りました。そして今、ＡＩを使えば、絵を描けなくても、プログラムしなくても、ＡＩに指図するだけで、ひとりで、そこそこのゲームを作れてしまいます。ホントびっくりです。ちなみに下のゲームの制作時間は、ほんの30分ほどでしたよ。あ、ブーストするボタンは押さないように。
https://t.co/slczyG52ZQ
— 堀井雄二 (@YujiHorii) October 11, 2026
The mystery is available through an Anthropic Claude Artifact. Horii’s estimate has not been independently verified, and the short development time should not be confused with the work required to produce a polished commercial release. The reporting indicates that AI assisted in creating the game; it does not establish that an AI model dynamically generates the suspect’s responses during play. The experiment builds on Horii’s previously expressed interest in conversational AI. At the 2025 G-Star gaming conference in South Korea, he discussed the possibility of using AI characters in quiz and mystery games, allowing players to investigate cases through conversation. In a subsequent report, he also expressed interest in incorporating AI into future games. Those comments demonstrate his curiosity about the technology, but do not confirm that a specific upcoming Dragon Quest title will use it.
Horii’s comparison with The Portopia Serial Murder Case is especially notable. The earlier adventure helped establish his reputation for narrative-driven game design. His latest experiment suggests that AI tools can lower some technical barriers between a designer’s concept and a playable implementation, although the creative decisions still depend on the person shaping the experience. The demonstration does not prove that AI can replace the people and processes behind large-scale game development. Commercial releases require extensive testing, iteration, performance optimization, localization and quality assurance.
Instead, Interrogation Room Komiya offers a more focused lesson: AI may let experienced creators test ideas much faster than traditional workflows allow. Horii’s 30-minute experiment is a demonstration of rapid prototyping, not evidence that a finished commercial game can be made in half an hour.
