If you get the problem that you cannot see the game window when you start the game try doing this:

goto ~/.config/unity3d/Failbetter Games/Sunless Skies/

and edit prefs file and put in your screen resolution in Height and Width (like below 2160 an 3840 for 4K screen):


<pref name="Screenmanager Resolution Height" type="int">2160</pref>

<pref name="Screenmanager Resolution Width" type="int">3840</pref>

Fixed the links for you ;)
GOG forum software is a strange beast, and mess up as soon as you try to put multiple links on a single line.

Thanks. I was about to return the game thinking my Intel graphics weren't handling it.

oblidor! Thank you for your clear complete description of the solution!

The "prefs" file problem still exists now, in October, when Sunless Skies is installed in Mint 19.2 (based upon Ubuntu 18.04).