Oxygen Not Included: Spaced Out! is a simulation game that expands the original's mechanics by introducing multi-world gameplay, allowing players to manage multiple colonies across different Planetoids. Players must balance the needs of Duplicants while exploring new biomes and securing resources from various planets, all in real-time. The game challenges players to build a thriving megacolony that can survive the harsh conditions of space.

The game features an expanded rocketry system, enabling the customization of modular rockets and an enhanced Starmap for exploration. Players can delve into a broader Research Tree with new mid-game Rocketry options, making resource management more strategic. Additionally, new critters and a variety of resources, technologies, and biomes enrich the gameplay experience, encouraging players to discover and adapt to the vast universe of Oxygen Not Included: Spaced Out!