Hello,
On Linux, when using the Steam builtin compatibility mode (I selected Proton 8 in the dropdown menu in Steam), the game ran perfectly apart from running out of video memory twice in my 14 hour playthrough (I finished the game). After running out of video memory, lowering the memory and resuming from my savegame fixed the problem.
However there was no audio. Other, non-Linux users seem to have this issue as well, as seen in the thread on the Steam forums[1]. A month ago a user posted a fix to the forum. A line of text had to be removed from the gameinfo.txt file. After the fix, everything worked wonderfully.
This is the fix: Go to "steamapps\common\G String\gstringv2\gameinfo.txt" then delete the "Game |gameinfo_path|" line inside SearchPaths.
This is the link the the thread, it goes directly to the post made by user "Roze magnetron":
https://steamcommunity.com/app/1224600/discussions/0/3732953219567622547/?ctp=2#c6975585346738902519
Since this bug seems to be a dealbreaker for people, I think it could be added to the wiki perhaps. It may be a recent regression.
I also wrote a report for Proton DB.
Note: On proton DB I see reports as old as three years. So the issue may have lingered for a while.