The game does not run out the box. Missing core fonts cause it to crash on startup. I used the same procedure for correcting fonts in Shadow Empire and this worked.

• Navigated to ~/.steam/steam/steamapps/compatdata/783210/pfx/drive_c/windows
• Deleted system32/gdiplus.dll
• Deleted syswow64/gdiplus.dll
• From a terminal, ran protontricks 783210 -q corefonts gdiplus.

With the correct/complete fonts installed, the game starts fine in Steam.

Before this, I tried installing .NET 4.7.2 as the game appears to use .NET. This did not seem to correct the problem; the cause seems to be directly related to missing fonts only.

I did experience one crash on a subsequent startup, but none since. Game runs correctly so far but it's early days.