Works the same as on Windows... which requires bypassing the dumbest DRM ever made
Game requires editing the Setting.lua file by replacing -- with just spaces and disconnecting from the internet to play. This isn't unique to Linux, but what's required on Windows as well.
Game isn't really recommended in general (didn't have a lot of fun with it), but if you have and want to play it, well, it works.
Displays error if you don't edit the settings file, crashes during cutscene even with
Comment out/disable NetFileURL and NetFileSkipIfNoConnection from the settings' LUA file from the globals folder
This is not a proton-specific problem. See https://steamcommunity.com/app/204760/discussions/0/792924952651389438/
Basically, you need to comment out NetFileURL and NetFileSkipIfNoConnection from globals/settings.lua in the game folder.
movies are not shown
Impossible to get to work without tinkering, even on Windows. The fix with the config might not be enough, you might need to firewall out biart7.com
still doesn't work with proton 5.13-4
also tried with PROTON_USE_D9VK=1 and PROTON_USE_WINED3D=1
Initialization error - popup message.