From an Idea to a Playable Game
At the start of August, the Online Warm-up Challenge invited builders to explore what happens when Codex becomes part of the game development process from the beginning.
The submissions covered a wide range of genres, mechanics, and visual styles. Some came from experienced game developers. Others came from people building a game for the first time. Each one showed a different way Codex can support the path from an initial idea to something people can play.
40 teams are now advancing to the final stage of OpenAI Game Builders Seoul.
How the Games Were Reviewed
Each submission was considered across five criteria published on the event website:
Playability, Originality, Codex Collaboration, Release Potential, Presentation
Taken together, these criteria provided a balanced view of each submission, including its playability, originality, use of Codex, presentation, and potential for further development. The overall assessment considered how these elements came together in each submission.
The 40 Shortlisted Teams
The list below is organized alphabetically by game title and does not indicate a ranking.
Game title (Team name)
10초만 왕국 (신대방 보드게임 동아리)
Canvas Commander (intermezzo)
cap-shift (Homegrid)
Eco Terrarium: Micro Evolution — 16종이 진화하는 유리병 생태계 (Buddypia)
EX.I.T. - EXTRICATION (Project 엑시트)
FLICK/STRIKE (FLICKER)
Grenade! (SillyToolValley)
HAP (합) (합)
I'm Just a Wall (Salt&Vinegar)
It's My Turn... Check! (바람을 가르듯)
LAST TRACK : PROTOCOL (우리가남이가)
LOADED (CHICKEN WIND)
Mecha Rampage: Siege Walker (MK486DX)
Metro Villain (지하철 빌런) (Annoying Cake)
OrbitOrbit (이프제로)
Pagebreak (코드어니언)
Paint MANY!MANY! (TheMANY (더마니))
Play the Wor!d (Sweet Turtle)
Rooftop Painter Tag (MAKE A WAY)
SHOEOUT ARCADE (OZYODA)
TIDESTEP 물때 (zzunkie)
WINDOW SHIFT (NIKO)
공룡달리기 · GongRyong Run (동그라미)
내림 — 저주를 먹는 자 (LYNGUN)
던전수쿠마 (Dungeon Sookuma) (쿠마 스튜디오)
등대섬 바다 이야기. (NullByte)
라벨렌 전기 : 겨울선 (뉴럴브레이크)
랜덤 전쟁:신의 신탁 (ROGAMES)
미기록 구역 (이세계 해적단)
발적화! (발적화!)
아르카나의 기록 (TEAM PANGU)
오늘도 수상한 전당포 (오늘도 피곤한 팀원들)
온리스쿼트 (온리스쿼트)
용사주식회사 (오디로그)
우물 안 개구리: 원소술사의 탈출 (우물 밖 개구리)
주차관리국 (The Parking Bureau) (MKKPLAY)
카고 엠파이어 (아이온랩스)
쿼터 아일랜드 (우마이 스튜디오)
프리즌 퀸 (쎄씨바나나)
피안화 ㅡ 꺼지지 않는 등불 (코딩하는 간호사)
Shortlisted teams will receive attendance and preparation details directly through the contact information provided with their submissions. Please check the relevant email inbox, including the spam folder, and keep an eye out for phone calls or text messages in case additional information is needed.
Venue access, presentation order, and other on-site details will be shared with shortlisted teams ahead of the event.
Next: One Day in Seoul
On August 31, the 40 shortlisted teams will come together in Seoul for a one-day, in-person event.
[ Track 1 ] From Zero to One: Build with Codex
A representative from each team will have up to three minutes to introduce the game created during the Online Warm-up Challenge.
The elevator pitch is a chance to share the game’s core idea, how Codex was used, what changed through iteration, and what the team learned along the way. Teams must complete the pitch to be considered in the final Track 1 judging.
Presentation format and elevator pitch requirement details will be sent directly to shortlisted teams.
[ Track 2 ] Go Full Codex: 5 Hour Build
Track 2 starts with a new theme revealed at the event. Participants will have five hours to turn that theme into a playable browser game with Codex. The format is intentionally fast: build, try, play, and iterate within a limited window. Participation in Track 2 is optional.
Invited Korean game industry Legends and Special Guests may also join the build. Guest entries are part of the experience but will not be eligible for awards.
Building the next way to build
Game Builders Seoul is exploring a different way to build games, one that brings ideas closer to play and creates more room for experimentation, learning, and creative expression.
Game Builders Seoul explores how Codex can change the way games are made, making it easier to bring more ideas into the world, help more people build, and give small teams room to pursue ambitious work. A small team can carry a bold concept further. A first-time builder can give shape to an idea. An early project can become the first step toward something new.
Every submission adds to that exploration. Together, these games show not only what builders made, but how the creative process can change when Codex becomes part of the work from the beginning.
On August 31, 40 teams will bring their games, ideas, and stories to Seoul. The final stage will be a chance to play what they built, and to see what becomes possible when more ideas can become real.
Thank you to everyone who took part in the Online Warm-up Challenge.
Build with Codex, Play with Hive.
Information for Shortlisted Teams
Attendance confirmation and preparation details will be sent directly to the contact information provided with each submission.
Venue access, presentation order, and other on-site details will be shared directly with shortlisted teams.
Participation and final judging are subject to the event Terms and instructions provided to participants.
The schedule and event format may change if needed. Any updates will be shared directly with the teams.