No, those games are single-player games without anti-cheat. It’s possible that Proton has issues with older Intel processors or integrated GPUs or something. The games just don’t get running most of the time. Fortunately Battle Brothers still runs.

Don’t ask me what the fuck is broken with it, but it is. Proton may work better on newer systems with more cores in the processor, but it certainly has some black spots in terms of retro-hardware-compatibility apparently.

I don’t know exactly, because nobody wanted to help me troubleshoot the problem so I just gave up.