Hello @naoliv, while PROTON_USE_WINED3D=1 can be useful for troubleshooting, it is not considered a supported option. In general, the lack of Vulkan support for the Intel Sandybridge generation graphics in your system makes it unsupported by Proton.
There's a good chance this is an upstream issue with wined3d, which if you reproduce with it with vanilla wine, then it can be reported to https://bugs.winehq.org/ and the fix will eventually make it downstream to Proton in a future major version update.
PROTON_USE_WINED3D=1`x2 2021-05PROTON_LOG=1`x1 2021-05
Compatibility Report
System Information
I confirm:
Game was run with
PROTON_USE_WINED3D=1PROTON_LOG=1output: steam-485360.log.txtSymptoms
Game is all red:

Reproduction
Always reproducible. Just needs to run the game.