Unbounded is an innovative infinite game that transcends the limitations of traditional finite, hard-coded systems by utilizing generative models. Inspired by James P. Carse's distinction between finite and infinite games, this game employs cutting-edge generative AI technology to create a character life simulation fully encapsulated by generative models. Drawing inspiration from sandbox life simulations, Unbounded allows players to interact with autonomous virtual characters using natural language commands, engaging in activities such as feeding, playing, and guiding characters, all facilitated by an open mechanism generated by large language models (LLMs), some of which may be emerging technologies. The development of Unbounded involved technological innovations in LLMs and visual generation, including a specialized, distilled large language model for real-time dynamic generation of game mechanics, narratives, and character interactions, as well as a new dynamic area image prompt adapter (IP-Adapter) to ensure visual consistency yet flexibility of characters across various environments.