Yuji Horii releases new AI-generated Dragon Quest game he made in 30 minutes

By Mason Cook•12 October 2026

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Dragon Quest co-creator Yuji Horii has released a text-based interrogation game that he says was created using generative AI in about half an hour.

In a post over the weekend, the developer recalled making The Portopia Serial Murder Case in 1983 largely on his own. “I came up with the story myself, drew the pictures myself, did the programming myself, and created the game all by myself,” Horii wrote on X.

“And now, by using AI, even if I can’t draw pictures or program, I can just give instructions to the AI and create a decent game all by myself. It’s truly astonishing. By the way, the production time for the game below was just about 30 minutes. Oh, and don’t press the boost button,” he added, linking to the text-based interrogation game.

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。

Yuji Horii, on X

Horii’s interest in the technology dates back a while. Earlier this year, MMO Dragon Quest 10 teamed up with Google’s Gemini AI to power an NPC chatbot called “Chatty Slimey”, an in-game character that can talk to players.

The 72-year-old defended the decision in an interview with Famitsu, translated by GamesRadar. “Because nowadays AI is really smart, it’s fun. It doesn’t matter what I ask it, it hardly ever makes things up [anymore]… It’s evolving, and lately there are a lot of things you can do with it. Slimey is a conversational partner, so I think lowers the barrier of entry to interacting with AI,” he said.

As noted by VGC, Horii is also considering an AI-powered chatbot for one of his future games. He is currently involved with Dragon Quest 12: Beyond Dreams and a surprise sequel to The Portopia Serial Murder Case.

Generative-AI and its uses in game development have been hugely controversial in recent years, with players, developers and video game actors worried about job security. Just this month, Google and Unity revealed a quite depressing AI-game-making tool.