The headline number: 37 GB down to 18 GB
Obsidian lists the change under "Tech Upgrades" in its patch notes: reduced file size on all platforms, 51% smaller on PC, from 37GB → 18GB, 200-300mb smaller on consoles, upgraded to Unreal 5.7, and various large performance improvements.
Two points matter here:
- The console saving is a range. iXBT says the console version now takes up 300 MB less. Obsidian's own figure is 200 to 300 MB, with no breakdown by console model or a separate PS5 number. Saving a few hundred megabytes on consoles is nice, but it's small compared with the 19 GB saved on PC.
- This is an engine upgrade, not a new port. Obsidian's wording is "Upgraded to Unreal 5.7." The game was already on PlayStation 5. According to the update tracker Sourceborne, PS5 Early Access arrived with the 11 August 2026 stable major update 0.5 / Into the Abyss. Rot and Ruin moves every existing version to a newer engine release. It doesn't bring the game to a new platform.
Neowin's report gives some useful background: the game has been receiving a steady stream of updates since its early access launch last year, and that means the install size has been going up as well. Live-service games usually grow with every patch. One that shrinks by half is unusual enough to be worth a note on any SSD you track closely.
What PC players should expect on update day
According to Neowin, the smaller install has a one-time cost: the game will redownload from scratch, but it will be that 51% smaller 18GB package. Obsidian's notes don't say this themselves, so treat it as Neowin's reporting rather than an official instruction for every storefront. If it holds true, here's what it means:
- Plan for a full download, not a small patch. If you're on a metered connection, a mobile hotspot or slow rural broadband, budget for roughly 18 GB of data.
- Don't assume the download size equals the install size. The 37 GB and 18 GB figures describe how big the game is installed. Neither Obsidian nor Neowin says how much free space the update needs while it's applying, so leave some headroom.
- Check your saves before the update kicks off. Neither source says saves are at risk. But if you keep manual backups of local saves for any survival game, doing it before a full reinstall is cheap insurance.
Once it's finished, the library entry for Grounded 2 in the Xbox app or Steam should show a much smaller install than before.
Obsidian doesn't say how it got the size down. The notes don't mention new compression, asset deduplication or repackaging. Anyone saying it was all down to Unreal Engine 5.7 is guessing.
Performance claims: promising, but unmeasured
The notes promise "various large performance improvements" but include no frame-rate figures, loading-time comparisons or hardware-specific results. Treat it as a developer claim until players and benchmarkers test it on real hardware.
There's more concrete evidence in the stability section. Obsidian lists fixes for several crashes on PS5 and PC, covering buildings, visual effects, status effects, creature AI and loading saves. It also fixes a performance drop around Slime Mold Stalks and many cases of clients rubber-banding during multiplayer. Cross-platform fixes are listed too: one for a crash when a PS5 player joined a Playground hosted on Xbox Series X, and one for an issue that left Shared Worlds accessible on PS5 with crossplay disabled.
None of this means every crash or stutter is gone. It does suggest the engine move came with real stability work.
The content side of Rot and Ruin
The technical changes shipped alongside a large content update. Xbox Achievements reports the update expands the garden-based survival game with a new Woodpile area to explore, the return of Termites, and a Centipede boss. In the Woodpile, players encounter Termite Workers, Soldiers, and the Termite King, as well as O.G.R.R. variants and the aforementioned Centipede boss.
Other additions:
- Potato Beetle Buggy: a close-range combat mount that fires a spread of projectiles and has a healing ability. Obsidian says it can also haul resources and contribute materials to blueprints.
- Painting: players craft paint and apply it with a paintball gun called the Splotcher to walls, floors, roofs, stairs, doors and other structures.
- Gear progression: weapons and armor can be upgraded to higher Tiers using Bismuth, a new resource connected to the strange forces of Raw Science beneath the Park. Gather it, refine it, and put it to work at the new Yoking Press
- New mechanics and resources: the notes list a Perfect Dodge in which player takes no damage; stamina is not consumed, allowing player to counter-attack immediately. They also list Bismuth and Spew spores as new resources.
- Collectibles: eight SCA.B color schemes and five figurines that can be built as statues in your base.
The patch notes also include a long list of fixes for quests, buggies, building, UI, audio, and spots where players could fall out of the world.
Where it's available
Gameoneer reports that Rot and Ruin is live now on Steam Early Access, Xbox, Game Pass and PlayStation 5, with the full release of Grounded 2 expected in 2027. On the Xbox side, Xbox Wire lists Xbox Series X|S, Xbox on PC and Game Pass. The game is still in Game Preview and Early Access.
The update went through public testing first. Sourceborne records that Obsidian opens Rot and Ruin 0.6.0 for public testing on 6 October 2026. The full release followed on October 20. The final patch notes include a "PTB to Live" section of fixes for problems found during that test.
iXBT also reports a 9.56/10 user rating on the PlayStation Store. We haven't been able to confirm that figure, and store ratings change constantly.
Why this matters beyond one survival game
Unreal Engine games aren't usually known for slim installs, so a first-party Xbox Game Studios title halving its PC footprint mid-Early Access is worth noting. Neowin also points out that the game now runs on Unreal Engine 5.7 as well, which keeps the game on a current engine release while it's still in development. That's arguably easier to do before 1.0 than after.
Engine upgrades in the middle of development also carry risk. New engine versions can bring new bugs as well as fixes, which is probably why Obsidian ran a public test first. The full-redownload requirement Neowin describes is also a real cost for players on capped or slow connections.
The bottom line
- PC: the install drops from 37 GB to 18 GB (51%). Per Neowin, getting there means a full redownload.
- Consoles: a modest 200 to 300 MB saving, not a flat 300 MB.
- Engine: an upgrade to Unreal Engine 5.7 across all versions, not a new PS5 port.
- Performance: Obsidian promises big gains but hasn't published benchmarks. The crash and multiplayer fixes are specific and documented.
- Content: the Woodpile, Termites, the Centipede boss, the Potato Beetle Buggy, painting, and Bismuth gear upgrades.
If your SSD is nearly full, this update frees up about 19 GB once the redownload is done.