Hi, This Tutorial was made before the release of Nier Replicant,
So I don’t know if It would work with Proton but Anyway.
Due recent pc reviews, It say this game doesn’t have vsync, and the game animation/gametime is accelerated above of 60fps
But on GNU/Linux doesn’t exist Rivertunner or Nvidia FPS Cap Settings, So
If you want cap your fps, you need a program called libstrangle,
Which you can get from here:
You can install building yourself (read the README.md for more information) or use a Package (if you don’t find below or searching on the Internet, you can build it).
Here a List of known packages for some distros.
When you have installed:
Set the Launch Option as:
STRANGLE_VSYNC=2 strangle 60 %command%
And now your FPS are capped and the game should work fine (If Proton not crash before)
UPDATE: This Game Works with Proton-6.5-GE-2 without any issue with this solution. (at least first minutes) but stutter related with SteamInput (is also reported on Windows)