{"rewrite":{"id":"r_0bd65fab7ae959f9a8abe7fb","clusterId":"c_4345592b27f0dbc076f18890","slug":"mimesis-developers-detail-ai-native-game-design-at-first-japan-talk","model":"deepseek-v4-flash:free","headline":"MIMESIS Developers Detail AI-Native Game Design at First Japan Talk","summary":"ReLU Games and publisher KRAFTON held their first development talk session in Japan, where the team behind the cooperative horror game MIMESIS explained how it builds games around AI rather than using AI as an add-on. The studio, established in June 2023 as an independent KRAFTON subsidiary, reported that MIMESIS has sold over 2.1 million copies, with Japan ranking highest in Steam sales by country ratio. Director Ahn Jae-hon traced the game's origins to a failed prototype called Project Doppelganger, a versus action game where AI imitated combat styles. That project was shelved after the team realized the AI did not create new fun. In August 2024, market research showing co-op games accounted for 36 percent of Steam sales in 2023 despite being only 6 percent of releases led the team to pivot toward a horror, co-op, and comedy combination. The core mechanic became an AI that imitates teammates' voices and behavior, creating lasting distrust among players. The studio's prototyping culture centers on Seeds, five-day solo prototypes, supported by an internal tool called Nolan that automates builds and deployment.","whyItMatters":"The talk positioned MIMESIS as an AI Native game, meaning removing the AI would eliminate the core experience, a distinction the studio draws against AI Enhanced titles where AI merely improves existing mechanics.","webCardHtml":"\u003cp\u003eThe session featured Lee Gi-mun, AI Creative Team Leader at ReLU Games, and Ahn Jae-hon, director of MIMESIS. ReLU Games reported 51 members as of July 2026, with production, deep learning engineering, and business teams working together from early development stages. The studio\u0026#39;s Seed system allows any staff member, including non-programmers, to create playable prototypes within five days using AI agents. The internal Nolan tool automatically builds and deploys uploaded ZIP files, making games playable in browsers and allowing staff to download, modify, and republish derivative versions.\u003c/p\u003e\u003cp\u003eAhn explained that the first MIMESIS prototype could only fool players for about two seconds, but that brief illusion proved sufficient to generate prolonged suspicion. The demo version for Steam Next Fest in June 2025 included one map and four monster types, adjusted for higher incident density. For voice imitation, the team avoided LLMs and real-time voice generation, instead recording player audio and selecting playback based on conversation and game context. The game processes over 4,000 pieces of information for behavior imitation. An October update is planned, and console versions are under discussion within the development team.\u003c/p\u003e","blueskyPost":"MIMESIS director: the first prototype could only fool players for 2 seconds, but that brief illusion created distrust that lasted the whole game. The fun is not perfect imitation, it is the suspicion that follows.","twitterPost":"ReLU Games' Seed method: 5-day solo prototypes, AI agents for non-programmers, and an internal tool that auto-builds any uploaded ZIP into a playable browser game. MIMESIS came from one such Seed that failed as a versus game first.","threadsPost":null,"newsletterBlurb":"ReLU Games held its first Japan talk session, detailing how MIMESIS grew from a failed versus prototype into a 2.1 million-copy cooperative horror hit. The studio's AI Native philosophy and Seed prototyping culture took center stage, along with plans for an October update and possible console versions.","attributionJson":"[{\"source\":\"GAME Watch (Impress)\",\"url\":\"https://game.watch.impress.co.jp/docs/kikaku/2131640.html\",\"title\":\"AIでゲームを面白くする。ホロライブ実況で人気「ミメシス」開発スタジオが掲げる\\\"AI活用の信念\\\"とは？【講演レポート】\"},{\"source\":\"Game Spark\",\"url\":\"http://www.gamespark.jp/article/2026/08/07/170367.html\",\"title\":\"\\\"Experiences That Couldn't Exist Without AI\\\"? The Developers of 'MIMESIS,' Which Surpassed 2.1 Million Copies, Discuss Their Iterative Game Development Approach\"}]","lintFlagsJson":null,"lintHits":0,"costUsd":0,"inputTokens":11363,"outputTokens":1116,"status":"published","repairAttempts":0,"nextRepairAt":null,"factsAttemptedAt":1786105864,"createdAt":"2026-08-07T12:23:53.000Z","publishedAt":"2026-08-07T12:26:44.000Z","updatedAt":"2026-08-07T12:23:53.000Z"},"cluster":{"id":"c_4345592b27f0dbc076f18890","canonicalTitle":"「AIがなければ生まれなかった体験」とは？210万本突破『MIMESIS』開発陣が明かす、試作を重ねるゲーム作り","representativeArticleId":"a_e7233f98f076e9a32be53c9a","sourceCount":2,"writtenSourceCount":2,"writeAttempts":0,"isSolo":true,"entitiesJson":"{\"anime_titles\":[],\"manga_titles\":[],\"work_titles\":[\"MIMESIS\"],\"studios\":[],\"people\":[\"安田俊亮\"],\"type\":\"news\",\"domain\":\"games\",\"is_roundup\":false}","contentType":"news","status":"published","firstSeenAt":"2026-08-07T10:00:00.000Z","lastSeenAt":"2026-08-07T10:00:03.000Z","updatedAt":"2026-08-07T12:26:44.000Z"},"attribution":[{"source":"GAME Watch (Impress)","url":"https://game.watch.impress.co.jp/docs/kikaku/2131640.html","title":"AIでゲームを面白くする。ホロライブ実況で人気「ミメシス」開発スタジオが掲げる“AI活用の信念”とは？【講演レポート】"},{"source":"Game Spark","url":"http://www.gamespark.jp/article/2026/08/07/170367.html","title":"「AIがなければ生まれなかった体験」とは？210万本突破『MIMESIS』開発陣が明かす、試作を重ねるゲーム作り"}],"entities":{"anime_titles":[],"manga_titles":[],"work_titles":["MIMESIS"],"studios":[],"people":["安田俊亮"],"type":"news","domain":"games","is_roundup":false},"keyFacts":["MIMESIS has sold over 2.1 million copies, with Japan ranking highest in Steam sales by country ratio, followed by the United States, Russia, and South Korea.","ReLU Games was established in June 2023 as an independent studio under KRAFTON and had 51 members as of July 2026.","The Seed prototyping system creates playable game prototypes within five days, often by a single person, using AI agents.","MIMESIS does not use an LLM for its AI NPCs; behavior imitation processes over 4,000 pieces of information, and voice imitation plays back recorded audio selected by AI based on context.","An October update is planned for MIMESIS, and console versions are under discussion within the development team."]}