Hello @Slapdax, your Intel Ironlake (Gen 5) graphics chipset is likely to cause most games to have trouble with Proton due to it only supporting OpenGL 2.1. It is unlikely to work, but you may have luck with setting PROTON_USE_WINED3D=1 %command% in the game's launch options or some of the other env variables that are available to troubleshoot Proton issues.
Thank you! That fixed it :)
Compatibility Report
System Information
GPU:
Driver/LLVM version: 2.1 Mesa 19.2.0-devel - padoka PPA
Kernel version: 4.15.0-54-generic
Link to full system information report as NULL
Proton version:4.2-9
I confirm:
Symptoms
Wont launch in Proton and gives message seen in the attached image

https://store.steampowered.com/app/943700/
Reproduction