Factorio now runs natively on Steam Frame with its stable ARM update
Factorio 2.1 has reached the stable channel with native ARM64 Linux support, including Steam Frame. The update also brings months of factory improvements to players who stayed on version 2.0.

Factorio promotional screenshot supplied by Wube Software LTD.. Image: Wube Software LTD.
Wube's release announcement names Steam Frame, Apple Silicon MacBooks running Asahi Linux and Raspberry Pi headless servers among the supported uses. Native ARM support does not turn Factorio into a VR game.
The update makes space deliveries more flexible for existing factories
Space Age players can send several different items in one rocket launch and transfer supplies between platforms in orbit. Platforms can also accept imports from any location, making fuel, ammunition and repair deliveries less restrictive.

Factorio promotional screenshot supplied by Wube Software LTD.. Image: Wube Software LTD.
A new unloading bay lets inserters move cargo directly from a landing pad into trains, belts or chests. Circuit improvements add more control over research, boilers and heat exchangers, alongside clearer separation of input and output signals.
Space platform balance changes include asteroid damage based on remaining health and drag based on mass instead of width. Space Age can now be played without Quality, with the Recycler separated into its own mod.

Factorio promotional screenshot supplied by Wube Software LTD.. Image: Wube Software LTD.
Existing saves can load but cannot return to version 2.0
Wube recommends backing up saves and blueprints before updating. Version 2.0 saves can load in 2.1, but some factory designs may break because of changed behaviour, including the circuit input and output split.
Once upgraded, saves and blueprints cannot be downgraded to 2.0. Some mods may also need updates, even though many popular ones were adapted during the experimental period.
For Steam Frame owners, this is another route to running a desktop game on the headset's ARM hardware. Valve has also been improving SteamOS streaming between Steam Machine and Steam Frame.