@gamingonlinux interesting, I played it yesterday and the performance was worse than on Windows. I have a Radeon 6700 XT and a Ryzen 5 3600.
I set everything to low and I couldn't get a stable enough FPS that my monitor's FreeSync premium would stabilize on 120 Hz.
this doesn't happen on Windows, there I get a smooth performance overall. I reported these issues on ProtonDB.
@xinayder not surprising - it was never designed specifically for linux and only just started working with Proton, so it will take time for Proton devs and graphics driver devs to optimize it