Once Human launched its ocean expansion, 'Isles of Abyss', on October 22. The update introduces ship building, ocean survival, and 4-player co-op raids across PC, mobile, PlayStation 5, and Xbox Series X|S.
The endgame content, 'The Sunken Lord', is conducted in a two-phase system on a 21-day cycle in which all players on the server cooperate. The faster players conquer the five regions and the 'Tower of Calamity' in Phase 1, the earlier they can enter Phase 2, where random corruption zones and the boss 'Calamity Owl' appear. Purification progress of anomalies is reflected in the server's shared progress, and once all progress is complete, players can awaken the final boss, 'The Sunken Lord'. Four players can then challenge a raid to breach the monster's shell, enter its interior, and attack its heart.
The expansion is set in an oceanic zone spanning the sea, islands, and underwater depths. In this setting, the sea itself is an ancient entity known as 'The Sunken Lord', which acts like a living organism that devours anyone crossing the region. Players learn navigation at the starting plains before mastering survival techniques required to navigate four hazardous regions.
The hazardous environments consist of 'Mist of Deceit', which blocks vision; 'Black Tide', which destabilizes sanity; 'Time Rain', which corrodes equipment while accelerating crop growth; and 'Skyfire', which erupts like a volcano. Each region is home to a massive biomechanical lighthouse known as the 'Tower of Calamity'. Destroying it with ships and personal firearms unlocks higher crafting tiers and permits travel to the next region. In Phase 2, the 'Tower of Calamity' mutates into an even more dangerous 'Abyssal Lighthouse'.
Out at sea, players can encounter five distinct ghost ships. They are tackled by disabling propulsion systems with broadside cannon fire, then boarding the deck to overpower corrupt crew members. Defeating ghost ships yields rare blueprints and mods.
Ships feature modular customization, allowing players to advance the ocean tech tree to upgrade propulsion or outfit vessels with cannons and harpoons. Decks can be equipped with automatic fishing nets, smelters, generators, and workbenches, turning ships into mobile survival bases. Players across multiple platforms can also divide roles and strategies to take part in fleet co-op play.
The update also adds 'Duet', an environment-manipulating Deviation that alters weather and wind through music, as a catchable target. New festive items are also available through Halloween events and log-in rewards.
Along with the update, Once Human announced that it has been selected as the first participating game in the Green Game Jam 2027. Supported by the United Nations Environment Programme (UNEP), the Green Game Jam is an annual global environmental campaign run by the Playing for the Planet Alliance that delivers environmental messages through video game content.
As its first initiative, the game is running 'Mr. Wish's Drift Bottle', a community environmental campaign tied to the Deviation 'Mr. Wish', through November 20. In this event, players share true stories of environmental recovery and send their stories out to sea. Participants can receive in-game rewards such as cosmetic charity crates, and standout stories will be featured across the community.
