Hello,
You should update your mesa drivers as other member reported this game as working fine.
Installed Mesa 18.3.0-devel - padoka PPA
glxinfo output
I can see same glitches.
Glitches were solved by PROTON_USE_WINED3D11=1 %command%
Hello @WinPooh32, we'll be using one issue report per unofficially supported game title, so I've gone ahead and transferred this issue report to https://github.com/ValveSoftware/Proton/issues/67#issuecomment-416249635.
That said, this reads like there's an mesa/intel/anv driver bug and should also be brought to the attention of your video driver vendor.
PROTON_USE_WINED3D11=1x1 2018-08PROTON_USE_WINED3D11=1 %command%x1 2018-08
Game looks working but it is not playable due to some graphics glitches.
Short video: https://youtu.be/ovBmObU0cMQ
System information