OpenGame: Open Agentic Coding for Games

Yilei Jiang, Jinyuan Hu, Qianyin Xiao, Yaozhi Zheng, Ruize Ma, Kaituo Feng, Jiaming Han, Tianshuo Peng, Kaixuan Fan, Manyuan Zhang, Xiangyu Yue*

CUHK MMLab yljiang@link.cuhk.edu.hk, xyyue@ie.cuhk.edu.hk *Corresponding author

An open-source agentic framework for end-to-end web game creation from a prompt.

Abstract

Game development sits at the intersection of creative design and intricate software engineering, demanding the joint orchestration of game engines, real-time loops, and tightly coupled state across many files. While Large Language Models (LLMs) and code agents now solve isolated programming tasks with ease, they consistently stumble when asked to produce a fully playable game from a high-level design, collapsing under cross-file inconsistencies, broken scene wiring, and logical incoherence. We bridge this gap with OpenGame, the first open-source agentic framework explicitly designed for end-to-end web game creation. At its core lies Game Skill, a reusable, evolving capability composed of a Template Skill that grows a library of project skeletons from experience and a Debug Skill that maintains a living protocol of verified fixes—together enabling the agent to scaffold stable architectures and systematically repair integration errors rather than patch isolated syntax bugs. Powering this framework is GameCoder-27B, a code LLM specialized for game engine mastery through a three-stage pipeline of continual pre-training, supervised fine-tuning, and execution-grounded reinforcement learning. Since verifying interactive playability is fundamentally harder than checking static code, we further introduce OpenGame-Bench, an evaluation pipeline that scores agentic game generation along Build Health, Visual Usability, and Intent Alignment via headless browser execution and VLM judging. Across 150 diverse game prompts, OpenGame establishes a new state-of-the-art. We hope OpenGame pushes code agents beyond discrete software engineering problems and toward building complex, interactive real-world applications.

📢 News

• [2026-04-21] 🚀 We have officially released the OpenGame framework! You can now access our Project Page, read the arXiv Paper, and start generating your own web games end-to-end.

Playable Demos

A curated gallery of web games generated end-to-end by OpenGame from a single prompt. Hover any tile to preview the gameplay; click through for the live build or the full source archive used by the agent.

  Marvel Avengers: Infinity Strike
  
  
  
    Prompt: "Build an epic side-scrolling action platformer starring the Avengers. I want to select between Iron Man (lasers & flight), Thor (hammer melee & lightning), or Hulk (smash attacks) to fight through 3 distinct levels: a ruined City, a SHIELD Helicarrier, and finally