Once Human's Isles of Abyss Expansion Turns the Ocean Into a Staring Hazard

Once Human moved its post-apocalyptic survival loop out to sea with Isles of Abyss, the largest free expansion in the game's history, which launched October 21. In an Xbox Wire breakdown, lead game designer Vincent Tao explains how Starry Studio built an ocean that isn't just the gap between islands.

The team wanted "the ocean itself to actively hunt you," Tao writes — and in Isles of Abyss, the sea is literally a living thing.

The details

• Released: October 21, 2026; free expansion, with full cross-play
• Map: five marine sectors, each built around stripping away a different survival crutch
• Features: modular ship building, 4-player raid against The Sunken Lord, seabed diving
• Game Pass perk: Ultimate members can claim a launch bundle through November 18, 2026

How the sea was built

The design started not with reefs or naval maps but with an image from H.P. Lovecraft's The Shadow Over Innsmouth: a lighthouse standing somewhere it shouldn't, watching. In the expansion, the ocean is a colossal living organism called The Sunken Lord. Its lighthouses are glaring eyes that track you, and its ghost ships — with names like Sworn Never to Port and No Return Voyage — drift like displaced organs that have forgotten how to make landfall.

Each of the five sectors takes something away: your vision, your sanity, your sense of direction, your prized gear, or stable ground. Progress comes from destroying Towers of Calamity to unlock new tech, boarding ghost ships for rare loot, and diving to the abyssal seabed for components.

Getting around runs on the game's modular building system, now extended to the water: anything from fast, stripped-down skiffs to multi-deck floating fortresses with naval cannons, crafting benches, and diving rigs. The climax is a four-player co-op raid that breaches The Sunken Lord's outer perimeter and fights through its tentacles and chambers to reach its heart.

What's in the Game Pass perk

Xbox Game Pass Ultimate members can claim the Once Human launch bundle from the Perks gallery until November 18. It includes the base game plus the Isles of Abyss Bonus Pack: one of seven Morphed Deviations, an Ocean Survival Supply Bag (10 Purified Water, a Compact Water Filter, a Basic Diving Suit, and 5 Antibiotics), and 2,000 Starchrom — limited to one claim per account across platforms.

Why it matters

Naval expansions in survival games tend to drown in dead space, treating water as a buffer between the real content. Making the ocean itself the antagonist — with ship crafting, layered exploration, and a raid set inside the sea's own body — is Once Human's bet that open water can carry the same tension as land, for the price of nothing.