Under Steam Settings -> Steam Play enable Steam Play for all titles:
You may have to check the first check box as well.
The version of proton here is not important, but generally I'd recommend the first option after "Proton Experimental".


Now SupCom:FA will download, but crash immediately. To fix that, open the game properties and check "Force the use of a specific Steam Play compatibility tool". Then choose "Proton 5.0-10".
That is the last steam setting you need to change.


At this point SupCom:FA should run, but it will be extremely sluggish whenever a video plays. My best workaround is disabling all videos.

To do that open the game properties, go to the "Local Files" tab and press "Browse Local Files...". Then simply rename the folder "movies" to "movies_bak" or something similiar.
You may have to repeat this step after an update.

Unfortunately this makes the campaign hard to follow, but at least it is playable. Maybe watch a playthrough on YouTube if you are interested in the story:
UEF Campaign
Cybran Campaign
Aeon Campaign
https://www.youtube.com/watch?v=PgzihrrdtM0
Also you might "get stuck" on a black screen when a video was supposed to play. Simply press Enter a few times to skip ahead.

Other than that I didn't notice any problems.

Enjoy :3

I tested it on Ubuntu 20.04 in November 2021. It worked fine, but it might be different in the future or on other versions of linux.

On the very top left of the Steam window click on "Steam", then Settings in the list that appeared.

Go to the game in your library. On the right, below the banner image, is a button with a little gear. Click it, then choose Properties in the list that appeared.

It is a piece of software that allows windows games to run on linux. Different versions work with different games, so some experimentation is required. Some games, especially those with DRM, might not run on linux even with Proton.

Follow this guide, but apply it to the game you're interested in. In the game properties choose "Proton Experimental" and try to run it. If you run into issues, try the next Proton version in the list.
Proton 5.0-10 seems to work with a lot of older games. You can also search the games' discussions forum for "linux" and see if someone suggests a Proton version to try.

If you find a version that works, be nice and tell other people about it. Feel free to use this guide as a template or simply make a quick post in discussions.
If you can't get it to work, you might have to wait for new versions of Proton to try. You could also google "<game name> linux" or something similar to see if there are other ways to get it to work.