The emergence of Large Language Models (LLMs) enables the redefinition of Non-Player Characters (NPCs) in video games as generative agents, overcoming the limitations of traditional scripted behaviors. However, current applications of generative agents often lack deep integration with core gameplay mechanics, limiting their impact on replayability and fun. To address this gap, we introduce MiniBistro, a Unity-based 2D business simulation where players manage operations through natural language interactions with waiter and customer agents, navigating challenges like service efficiency and customer complaints to achieve business growth and reputation success. We provide the source code and an interactive demo at https://github.com/MajestyHenius/MiniBistro.