The only hint i found in the log is this:

Assertion 'pa_atomic_load(&(c)->_ref) >= 1' failed at ../pulseaudio/src/pulse/context.c:1055, function pa_context_disconnect(). Aborting.

I managed to launch it on Lutris once and it worked fine except there was no audio during animated cutscenes. So i suspect this is definitely an issue concerning pulse audio.
steam-338930.log