MIMESIS is a cooperative horror game developed by ReLU Games and published by KRAFTON, in early access on Steam since October 2025, with over 2.1 million copies sold. It has received a major update and won the Excellence Award in the Game Design Division at the CEDEC Awards 2026.
MIMESIS is a cooperative horror game built around an AI that mimics players' voices and behavior, creating distrust among teammates. The game entered early access on Steam in October 2025 and has sold over 2.1 million copies, with Japan ranking highest in Steam sales by country ratio. It has maintained a 'Very Positive' rating from over 7,000 user reviews.
The game's development is rooted in ReLU Games' AI-native design philosophy, which treats AI as the core experience rather than an add-on. 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 game's success has been recognized with the Excellence Award in the Game Design Division at the CEDEC Awards 2026, and it was also a finalist for the Grand Prize. A major update on June 16, 2026 overhauled the AI monster's decision-making, added individual monster personalities, revised the game's progression from fixed 3-day cycles to a flexible structure, expanded dungeon interiors, and revamped the spectator system to let eliminated players possess monsters. The update boosted player numbers and sales, and a 30% off sale in June 2026 brought the price to 840 yen, its lowest yet.
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At a KRAFTON x ReLU Games talk event in Tokyo on August 5, ReLU staff detailed their AI game design approach, including the three principles behind their studio workflow and the development of the horror game MIMESIS. The game, which pits four players against an AI that mimics them, has sold 2 million copies on Steam since early access began in October 2025.
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.
Cooperative horror game MIMESIS has sold over 2 million units worldwide since its early access release last October. The game also won the Excellence Award in the Game Design Division at the CEDEC Awards 2026, recognized for its innovative use of AI that mimics players' voices and actions. The first major update last month boosted player numbers and sales.
ReLU Games has launched a 30% off sale on Steam for the cooperative survival horror game Mimesis, dropping the price to 840 yen until June 25. The game, which entered early access in October 2025, also received a major update on June 15 that overhauled the game cycle and added new content.
KRAFTON JAPAN has launched the "KRAFTON Steam Publisher Sale 2026" on Steam, running from June 18 to June 26, 2026. The eight-day sale offers special prices on over 30 titles from KRAFTON, its creative studios, and partner studios. Featured games include the survival life simulation game "Dinkum," the rhythm action title "Hi-Fi RUSH," the pet-raising game "My Little Puppy," the sci-fi action game "MIMESIS," and the action RPG "Last Epoch." The maximum discount reaches 85% off on "The Callisto Protocol." During the sale, a separate promotion for "PUBG: BATTLEGROUNDS" gives players double G-Coin when they purchase the in-game currency. The event page also highlights upcoming titles, including the new game "Age Twisters" and a public test for the in-development "PUBG: Black Budget." Some titles may not be available depending on language settings, and discount periods for certain games may end on June 25.
KRAFTON JAPAN released a major update for the co-op horror game Mimesis on June 16, 2026. The update improves the AI-driven monster's decision-making, adds individual monster personalities, revises the game's progression from fixed 3-day cycles to a flexible structure, expands dungeon interiors, and revamps the spectator system to let eliminated players possess monsters.
KRAFTON Japan announced that the cooperative horror game MIMESIS, developed by ReLU Games, received the Excellence Award in the Game Design category at CEDEC Award 2026. The game was also selected as a finalist for the Grand Prize. The selection committee praised its AI-driven NPC that mimics player voices and actions, creating tension and unpredictability.