
-force-glcore46
The game sometimes has a blue tint to the whole screen, but it goes away after a few seconds. I only saw it happen on startup.
If the game doesn't work, try using -force-openglXY or -force-glcoreXY, where XY is your GPUs OpenGL version.
You can find that using "glxinfo | grep "OpenGL version"" in the terminal. I got this output: "OpenGL version string: 4.6.0 NVIDIA 550.120", so I used XY = 46.
-force-glcore46 worked for me, while -force-opengl46 did not.
The first time I played this game on Linux, it worked fine without any tinkering, but only after the second startup I needed to find all of those tinker steps to make it work again. The case may be, that on your machine this game will work fine immediately. Still, I reccomend using Proton instead of the native Linux version.
I got all of this info from this Steam Discussions post: https://steamcommunity.com/app/304650/discussions/0/343787283753247203/
It seems to be the only post on that forum regarding problems on Linux.

Installs and runs fine so far
No issues with saves/crashes like I had read Windows users were having recently.

Worked perfectly first time but every attempted load after has game trying to open on my secondary (left) monitor and then crashing.
The first time I played Sunless Sea launched issue-free onto my primary monitor. Haven't been able to get it to work again since. The game crashes (occasionally a blank screen and music will be heard first). When it crashes it causes the desktop to crash as well with the error "something went wrong" and the option the "log out" but the screen becomes so locked up it's impossible to do anything but a hard reboot. I've tried reinstalling, deleting files, various proton versions, verifying game files. At this point I've given up. I'm tired of rebooting my computer. The work arounds I've found are to unplug my secondary monitor or competely change my setup but I'm not doing that for one game. The problem seems to be the game wants to open at point 0,0 which is cauing all my issues.
Works almost perfecly
Cloud saves are broken, you need to load manually
Requires extra clicks to load saves, besides that everything works perfectly
One of the best games I have ever played. No user would notice the difference between Windows/Native/Proton
Loading a save from Steam Cloud will cause the screen to turn black and you will need to re-open the game. Fortunately this has an easy fix, just load your save manually. This is an issue in the Windows version as well, I've been told.

Game works native on Linux and on Proton out of the box. I installed manually D9VK and it worked as well fine with this DX9 to Vulkan translation.

I was having problems running the native Linux version: the game started, the initial text appeared, but then, as soon as I clicked to continue, it just crashed back to the desktop. I searched for a while for support but did not find a lot of information outside of some bug reports, mostly for Windows, so I decided: "Why not give it a try with Proton?", Re-downloaded the game and voilĂ the game worked flawlessly until now.