Core Systems & Mechanics
- Gameplay Loop: The loop is a fractal of crisis management. You solve for Oxygen, which creates Heat; you solve for Heat, which requires Power; you solve for Power, which creates Carbon Dioxide. It is a perpetual motion machine of “just one more fix.”
- Mechanical Depth: This is where ONI stands alone. Most games fake physics; ONI simulates them. The way different gases layer (CO2 at the bottom, Hydrogen at the top) or how different materials have specific heat capacities forces the player to think like a chemical engineer rather than a gamer.
- Balance & Fair Play: While the game is brutal, it is remarkably fair because it is deterministic. Failure is rarely due to bad luck; it’s almost always a result of a flaw in the player’s own logic or a failure to account for a long-term byproduct.
- Accessibility & Clarity: This is the game’s greatest hurdle. The UI is excellent, but the “hidden” knowledge required to succeed (like liquid locks or vacuum insulation) often requires a literal deep dive into community wikis. It’s a high barrier to entry that rewards the persistent.
Narrative & Aesthetic
- Thematic Integration: The theme of entropy is perfectly integrated. You aren’t just building a base; you are fighting the inevitable heat death of your closed system. The Dupes (Duplicants) feel like disposable cogs in a machine, which underscores the cold, scientific nature of the simulation.
- World Building & Lore: The lore is subtle, found in ruins and emails, suggesting a corporate-scientific dystopia. It provides just enough why to support the how without getting in the way of the engineering.
- Art Direction & Presentation: The Klei hand-drawn aesthetic provides a vital counterweight to the math. The whimsy of the Duplicants makes the soul-crushing realization that your base is slowly suffocating much easier to digest.
- Audio & Sensory Design: The music evolves as your colony grows, moving from simple acoustic strums to complex orchestral pieces. The sound of a gas pipe thrumming or a pump working provides essential tactile feedback to the player.
Overall Experience
- Longevity & Replayability: Between different asteroid types and the sheer variety of “builds” (e.g., a “Sour Gas Boiler” vs. a “Geothermal Plant”), you could play for 1,000 hours and still be refining your designs.
- Engagement: It sparks a rare kind of engagement: the shower thought problem-solving. You’ll find yourself in a meeting at work suddenly realizing why your cooling loop is backing up.
The Connoisseur’s Verdict
Oxygen Not Included is a rare example of Hard Sci-Fi design. It doesn’t treat the player like a consumer; it treats them like a tinkerer. It is a game for those who find beauty in a perfectly efficient pipe layout and who understand that in a closed system, waste is just a resource you haven’t figured out how to use yet.

