CPU: Intel(R) Core(TM) i7-4765T RAM: 16G SSD: KINGSTON SUV300S37A120G
Video: NVIDIA GeForce GTX 960 4G (nvidia-current 396.54)
OS: MagOS Linux 2016.64
DE: Plasma+compiz-fusion 1680x1050
Proton version: 3.7-8 3.16-4beta

I confirm:

• At first start game shows EULA and tries to install DirectX and net 4.0 (it fails). You can omit this step by pressing cancel on EULA page.
• Game works on Proton 3.7-8 but it's unplayable due to slow down. It happens even on minimal graphics settings
• Game works fine on Proton 3.16-4beta without any slowdown effect even on epic graphics settings.