[Game Update] - 462129

Release Date: 04/29/21

Update Information:

Hi space friends!

Temperatures are rising, baby Hatches are frolicking, and the musky smell of blossoming Dusk Caps is alight in the air… Either it's springtime, or the testing of Plant Mutations has begun!

Plant Mutations are a brand new feature that integrates radiation with farming gameplay. There are now several strains of mutant seed that crop plants can drop when grown in radiation. Once analyzed at the new Botanical Analyzer, plants grown from these seeds will offer new trade-offs or efficiencies for your farms. Please let us know what you think and if you discover any issues as the system is still pretty rough and has plenty of room to grow!

There's a notable change to the conduction model of the Research Reactor resulting from a bug fix, so keep an eye out for updated tuning. There's also updated Rocket Port artwork, more worldgen tweaks (though nothing that should require a restart), as well as new and updated Codex entries.

We really appreciate your bug reports and love reading your thoughts, so thank you for taking the time to post in these forums and elsewhere.


What does this testing branch contain so far?

Here are the changes we've made so far in this update, loosely categorized:



  • Plant Mutation system allows specialized crop development
    • Exposing plants to radiation causes them to drop mutant seeds
    • Botanical Analyzer building will identify the traits of mutant seeds
    • Plant mutant crops for new tradeoffs and optimizations
  • Updated Codex entries, descriptions and lore
    • New plants
    • Cryotank
    • Radiation biome
  • Added Mud & Toxic Mud ambiences
  • Added sounds for Mud falling, landing and Dupe movement on Mud
  • New artwork for the Rocket Port Loaders

Changes and Improvements

  • Experimental: Allow temperature transfer of small ores less than 10 grams
  • Updated the Gassy Moo meteor artwork and impact animation
  • Added low coolant diagnostic criteria to Research Reactor
  • Research Reactor
    • Fixed issue with inconsistent coolant/reaction mass conduction
    • Enriched Uranium mass target increased 20x
    • Increased coolant/reaction mass conduction scale 5x
    • Meltdown temperature increased to 3000k
    • Added new meltdown animations
    • Fixed issue with temperature meter
    • Increased meltdown projectile mass

Bug Fixes

  • Fixed closing tag for Forest Moonlet string (for translations)
  • Fixed a world gen issue where the Frozen Slush subworld was unable to generate the proper geysers in some forest starts
  • Fixed failing to switch worlds after using dev debug
  • Fix animations rendering outside of the world
  • Plant sorting was broken on the planter box sidescreen, now the crops are consistently ordered
  • Moved uranium materials further in the build materials list
  • Fixed crash when dead Duplicant is hit by a Radbolt
  • Fixed issue where buildings with solid parts like the Solar Panel and Fish Feeder would leave behind a "ghost floor."



What is open testing?

"Open testing" means players get to test-drive new content early and give us feedback and suggestions before it goes live. Because this is an unfinished and in active development version of the game, it's pretty likely you'll encounter bugs, crashes or balance issues while playing these builds. We'll try to fix any problems that crop up as quickly as we can, but it's possible you'll lose progress in your games while playing on the Testing branch.

Regarding performance, the Testing branch has additional debugging tools enabled to help us track down crashes. This makes the game run more slowly than the live version of the game.

Please also be aware that once a save is loaded in the Testing branch, it cannot be reopened again in the previous Live branch or previous builds.

What do I do if I find a crash or a bug?

Post it up on the Bug Tracker and we'll fix it as soon as we can. If you can attach a copy of your save file to your report, that helps us even more as we can pinpoint the source of problem more quickly.

Do I have to play the open testing build?

Nope! If you'd prefer to only play a stable build, you can continue to play in the current Default branch until the game launches in full. Playing the Open Testing build isn't necessary, but it helps us a lot to receive your feedback and reports - if you're interested, try it out!

How do I become an open tester?

There's no sign up or registration for becoming an open tester. If you own Oxygen Not Included plus the Spaced Out! DLC and want to join the Testing Branch, all you have to do is play the Open Testing build on Steam.

How do I play the open testing build?

You can switch your branch on Steam using the instructions below:


How to change branches in Oxygen Not Included (Steam)

  • You must own the Spaced Out! DLC
  • In Steam, click on Library > Games.
  • Scroll down to Oxygen Not Included.
  • Right-click and select Properties.
  • Go to the BETAS tab.
  • In the dropdown, select the name of the branch you want to play. In this case, the branch name is "public_testing"
    • This branch does not require a password.
  • In that same Properties window, go to the Local Files tab and press "Verify Integrity Of Game Cache."
  • Your game will be updated to the the previous branch.
  • Launch and play Oxygen Not Included


You can join in the Discussion Topic here.
If you run into a bug, please visit the Klei Bug Tracker.