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Yuji Horii 12 Oct 2026, 17:30

Yuji Horii made an AI game in 30 minutes and references Portopia

Yuji Horii made an AI game in 30 minutes and references Portopia

Dragon Quest co-creator Yuji Horii says on X he made a game with AI in about 30 minutes, comparing it to The Portopia Serial Murder Case.

In the same post, Horii referred to The Portopia Serial Murder Case from 1983, which he says he made on his own at the time: he came up with the story, drew the graphics, and programmed the game himself.

Eurogamer also reports that Horii previously spoke positively about AI in Dragon Quest 10, although that earlier Famitsu quote is not fully included in the material provided.

What happened

Horii shared a post on X in which he said he had made a game with AI in “about 30 minutes.” He included a link to the game and warned readers not to press the boost button. In the supplied tweet text, Horii also wrote that back when he made The Portopia Serial Murder Case, he personally came up with the story, drew the visuals, and handled the programming, and that with AI he can now create a “decent” game by giving instructions without drawing or coding himself.

The post is dated 11 October 2026. Eurogamer published an article about it on 12 October 2026, with the 30-minute example at the center. In that article, the game is described as a text-based interrogation game, but that wording does not appear in the tweet itself and therefore comes from secondary reporting.

Eurogamer also says Horii had previously defended the use of AI in Dragon Quest 10. The site mentions a Google Gemini-powered NPC chatbot called Chatty Slimey. The full Famitsu quote is not included in the material provided, so only that secondary reference can be safely included here.

Timeline

  • 1983: Yuji Horii releases The Portopia Serial Murder Case and later says he handled the story, art, and programming himself.

  • 11 October 2026: Horii posts on X that he made a game with AI in about 30 minutes and warns readers not to press the boost button.

  • 11 October 2026: In the same post, Horii compares the AI experiment with his solo work on Portopia and says AI now lets him work without drawing or coding himself.

  • 12 October 2026: Eurogamer publishes an article about Horii’s AI game and refers to his earlier support for AI in Dragon Quest 10.

  • 12 October 2026: Eurogamer also mentions Chatty Slimey, an NPC chatbot reportedly powered by Google Gemini.

Background

Yuji Horii is the co-creator of Dragon Quest and one of the best-known names in Japanese game history. The Portopia Serial Murder Case is one of his early solo projects and serves in his post as the reference point for the difference between manual development and AI-assisted creation. In the tweet text, Horii emphasizes that he worked alone on three parts at once back then: story, visuals, and programming.

The supplied sources also mention Dragon Quest 10 as earlier context for Horii’s stance on AI. Eurogamer says he previously defended AI use there, but the exact wording from the Famitsu interview is not fully present in the available material. As a result, only the fact that Horii had already spoken positively about AI applications in a Dragon Quest context can be confirmed here.

The 11 October 2026 tweet is the only primary source in the dossier. It explicitly states that the game Horii mentions took about 30 minutes to make, and that he finds it notable that AI now lets him build a “decent” game without doing the drawing or programming himself. The link in the post points to the game itself, but its title and genre are not separately confirmed in the supplied material.

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Sources