"Oxygen Not Included" is a simulation game developed by Klei Entertainment, where players manage a group of colonists in an underground asteroid. The goal is to ensure their survival by providing essential resources like oxygen, food, and water, while also maintaining a sustainable environment. Players must build and upgrade their base, explore the surrounding areas, and research new technologies. The game features various challenges, such as managing temperature, pollution, and stress levels among the colonists. Strategic planning and resource management are key to thriving in this complex, ever-changing environment.