Tencent has introduced GameGen-O, the first diffusion transformer model tailored for the generation of open-world video games. This innovative model facilitates high-quality, open-domain generation by simulating a wide array of game engine features, including dynamic characters, environments, complex actions, object control, and scene control with interactive controllability. GameGen-O leverages Tencent's massive proprietary data set and involves contributions from multiple AI research teams within the company. The model is expected to revolutionize virtual world modeling and game creation, allowing for the generation of entire open-world video games with just a prompt. A YouTube promo showcasing the model has also been released.