Oxygen Not Included: The Prehistoric Planet Pack by Klei Entertainment places your colony on a primeval planetoid. It layers oxygen, heat, and resource puzzles with a doomsday asteroid mechanic that forces planetary defenses while testing base resiliency. The pack adds prehistoric flora and fauna, new processing buildings, and themed decorative items to alter base appearance. Aimed at veteran Duplicant managers seeking fresh mechanical challenges and a thematic departure from standard space colonies.

This expansion converts steady base management into a time-pressured objective

The pack moves a colony to the named planetoid Relica and introduces an incoming impactor, Demolir, which places a doomsday timer on play sessions. That timer forces players to combine long-term systems work with short-term defensive construction, and it requires reconsidering layout priorities as the colony balances oxygen, heat, and survival under an explicit external threat.

New resources, buildings, and fauna reshape midgame logistics

The pack introduces Peat as a multi-purpose organic material and several new processing buildings that alter production chains, including the Peat Burner, the Smoker, and the Emulsifier. Large domesticable creatures such as the Ceratop and Megasloth expand ranching, while carnivorous predators complicate animal husbandry. The DLC also adds dino-minded Duplicants like Maya and Higby, which affect crew composition and role choices.

Distinct prehistoric visuals and native plants widen replay options

Archaic aesthetics appear through decorative Fossil Displays and specialized rugs that change base presentation. The expansion includes three named biomes, the Garden, the Feather, and the Wetlands, and introduces ancient flora such as Bonbon Trees, Ovagro Nodes, and Sweatcorn Stalks. Those environmental and cosmetic differences encourage different production strategies and visual themes across multiple runs.

In summary, a rewarding expansion best for experienced colony managers

The pack is a strong choice for veteran Duplicant managers who enjoy added mechanical risk and a thematic shift, supported by a positive player rating and designed compatibility with both the base game and the Spaced Out! expansion. Available on Windows and compatible with macOS and Linux, it suits players ready to deepen campaigns; newcomers should learn the base game before adding expansions.