Complete DLC Ecosystem (as of October 2026)
- Spaced Out! (December 2021) - Major expansion adding multi-asteroid gameplay, modular rocketry, radiation mechanics, new biomes, critters, and a revamped Starmap. Considered practically essential for the mid-to-late game experience.
- The Frosty Planet Pack (July 2024) - Ice planet starting world with three new biomes (Ice Cave, Cool Pool, Nectar), critters (Flox, Bammoth, Spigot Seal), buildings (Wood Heater, Snow Tile, Deep Fryer), plants (Pikeapple Bush, Alveo Vera, Sherberry, Plume Squash, Bonbon Tree, Idylla Flower), and new elements (Cinnabar, Tallow, Nectar).
- The Bionic Booster Pack (December 2024) - Introduces six Bionic Duplicants with internal oxygen stores, 16+ bionic Booster modules, a unique Bionic Skill Tree, Power Bank portable energy system, remote-work buildings (Remote Controller, Remote Worker Dock), Flydo work drone, Robo-Pilot modules, and maintenance buildings (Gunk Extractor, Lubrication Station). New elements: Phyto Oil and Gunk.
- The Prehistoric Planet Pack (June 2025) - New starting world "Relica" with an impactor asteroid threat. Features biomes (Garden, Wetlands, Feather), dinosaur-like critters (Lumb, Rhex, Jawbo, Dartle, Gnit), new buildings (Emulsifier, Peat Burner, Smoker, Blastshot Maker, Meteor Blaster, Fossil Block), and new elements (Peat, Amber, Shale, Nickel Ore, Resin, Biodiesel, Iridium). Two new Duplicants: Maya and Higby.
- Neutronium Cosmetics Pack (November 2025) - Cosmetic blueprints with regal neutronium-themed restyling options for buildings, jet suits, atmo suits, and a new Duplicant.
- The Aquatic Planet Pack (June 11, 2026, $9.99) - New starting world "Marinea" (plus Marinea Minor and Marinea Fragment for Spaced Out!) split into four biomes: Beach, Reef, Kelp Forest, and Abyss. Adds swimming as a core mechanic for the first time in ONI history. Critters: Blowter, Beakon, Slogo, Gildgo, Seaquine, Orehull, Kelpole, Glo Squid. Plants include Tower Kelp, Flue Coral, Mussel Sprout, Sodicane, Starnacle, Clampum, Gum Palm, Bulbloom. New elements: Coquina, Corallium, Zinc Ore, Zinc, Basalt, Galena, Siltstone, Rubber, Latex, Ovolene, Mucin, Squid Ink, Polluted Brine. Two new Duplicants: Kai (starter) and Minnow (an "Unknown" survivor who joins after completing the asteroid imperative).
Current Stable Release - U59, The Aquatic Planet Pack Update (U59-736649, hotfixed through 744825):
- Swimming System - Duplicants can now swim, with two trainable skills: Basic Swimming and Divemaster. Applies game-wide, not just to DLC owners
- Suffocation Overhaul - Duplicants become incapacitated when they suffocate instead of dying instantly; other Duplicants can perform CPR to revive them. Breath is now displayed as an integer rather than a percentage
- Free Buildings for Everyone - Aquatic Critter Fountain, Fish Pick-Up, and Insulated Conductive Wire + Bridge (a higher-capacity insulated power option for mid-to-late game grids)
- Plastic Gasket Substitution - Most buildings that previously required Plastic now accept Plastic Gaskets, including the Dehydrator, Rehydrator, and Steam Turbine
- Submergible Buildings - New "Submergible" build category; DLC adds Breathing Station, Aquatic Grooming/Shearing/Milking Stations, Vulcanizer, Tidal Turbine, Marine Drill, Sushi Bar, Mini Fridge, Wall Planter, Wide Hydroponic Farm, Glass Backwall, Glass Jelly Ceiling Light, Rubber Tile
- Rendering - Substantially improved liquid rendering with expanded textures and colors; underwater objects become more visible near the center of the camera frame
- UI - Search added across more screens; Dig Tool gained checkbox filters for uprooting plants and removing natural backwall; clearer input/output display for multi-input buildings
- Modding - ElementLoader converted to VYaml, cutting roughly two seconds off launch time; new KAnim shine effect system and music playlist hooks for mod authors
- July 12 Hotfix (740622) - Minnow's Freediver trait now grants +4 to all attributes while swimming; in new saves Minnow joins with +4 in all attributes and Ancient Knowledge 3
- July 28 Hotfix (744825) - Fixed incapacitated Duplicants teleporting to the bottom-left of the world after rescue/resuscitation; deconstructing Gasketed buildings now spawns a Gasket of the correct element instead of Genetic Ooze; fixed a liquid rendering bug on older graphics cards and a navgrid memory leak; optimized textures and the liquid texture array to reduce graphics memory usage. No further release has shipped since (last checked October 2026)
Previous Major Release - U58 March 2026 Bug Fix Update (U58-719533, hotfixed to 720697 and 722606):
- Unity Engine Upgrade - Major upgrade to Unity 6.3, the biggest engine change in ONI's history
- Temperature Exchange Overhaul - Removed the lower mass limit for temperature exchange; small masses (micrograms) now participate in thermal simulation, and the formula was tweaked for stability. This broke many advanced community blueprints (see Community Meta below)
- Off-Gassing Fixes - Fixed liquids emitting wrong gas amounts, wrong temperatures, or deleting mass entirely
- Gameplay Fixes - Wilted plants no longer consume fertilizer; entombed batteries no longer function; open doors no longer transfer temperature in vacuum; Pitcher Pump volume and stuck-Duplicant bugs resolved
- Modding Support - Harmony upgraded to 2.4.2; new Mod Safe Mode loads if the game crashes before the main menu; .NET Standard 2.1 became the recommended target
Away Team - ONI Spinoff Game (in development)
- New ONI Adventure - Direct-control, side-scrolling survival/base-building game set in the ONI universe where you pilot a single crash-landed Duplicant on a fully simulated world
- Same Simulation Engine - Full physics simulation for water, temperature, gases, and chemical reactions in a 2D side view
- Co-op Confirmed - Klei announced online co-op multiplayer at the April 9, 2026 Triple-i Initiative showcase, after a technical assessment of the simulation engine. Co-op is still in development
- First Playtest Completed - The closed single-player playtest (roughly 50 cycles of content) ran from the April announcement through its close on September 8, 2026; 877 of the ~1,000 invited participants took part. Klei is now incorporating playtest feedback
- Status - No release date announced; still listed as "coming soon" on Steam and klei.com
Klei Entertainment News (2026)
- Don't Starve Elsewhere - Revealed at the Triple-i Initiative showcase on April 9-10, 2026. Klei's first new in-house Don't Starve game since Don't Starve Together, featuring a procedurally generated world and online co-op. No release date yet
- Klei Fest 2026 - Studio-wide celebration and catalog-wide sale beginning June 11, 2026, timed with the Aquatic Planet Pack launch. Also brought updates for Rotwood and Don't Starve Together
- Ongoing ONI Support - Klei continues active development with content packs, free base-game updates, and regular hotfixes
Current Game State (October 2026)
- Six Active DLC Packs - One major expansion (Spaced Out!) plus five content/cosmetic packs
- Stable Build - U59 (Aquatic Planet Pack update, June 11, 2026) hotfixed through 744825 on July 28 is the current stable version; no newer major update has shipped since, and none has been announced
- Free Content Cadence - Klei's pattern of shipping a substantial free base-game update alongside each paid pack continued with U59 (swimming, CPR/incapacitation, insulated conductive wire, plastic gaskets)
- Modding Scene Stabilized - The Unity 6.3 / Harmony 2.4.2 transition from U58 has largely settled; Mod Safe Mode helps players recover from mod crashes, and U59's VYaml ElementLoader change is another item mod authors need to account for
- Community Meta - Spaced Out! remains essential. The U58 temperature exchange changes permanently retired many exploit-dependent blueprints (steam vent tamers like Luma's CSV tamer and the Tuxii eVent, door-based displacement pumps, single-door crushers, high-differential insulation tricks); replacement designs that avoid rounding exploits have since circulated. U59's swimming and CPR changes soften early-game drowning and suffocation deaths. Core beginner/intermediate strategies (two-tile airflow gaps, liquid locks, Hatch ranching) remain unchanged.
Development History & Milestones
- Base Game Launch - July 30, 2019 (exited Early Access)
- Spaced Out! Launch - December 16, 2021
- Sweet Dreams Update (October 2022) - Story Trait system, Somnium Synthesizer, Critter Flux-O-Matic, Kitchen Room, Spice Grinder
- Planet Pack Era (2024-2026) - Shift to smaller, focused DLC content packs alongside free QOL updates
- Away Team Announcement (June 2025) - First ONI spinoff game revealed; co-op confirmed April 2026
Technical Notes
- Engine - Unity 6.3 (upgraded in the March 2026 U58 update)
- Mod Support - Steam Workshop and manual installation; Harmony 2.4.2; Mod Safe Mode for crash recovery; .NET Standard 2.1 recommended; ElementLoader now uses VYaml as of U59
- Save Compatibility - DLC content can generally be added to existing saves, though new starting worlds require new games
- Performance - November 2025 brought pathfinding and simulation optimizations; U59 improved liquid rendering and cut ~2s from launch time via the VYaml loader
- Platforms - Aquatic Planet Pack is available on Steam, Epic, and WeGame; base game required
Updated: 2026-10-01
