I think I found the issue:
38749.602:0027:0028:warn:module:load_builtin_dll cannot open .so lib for builtin L"Steam2.dll": /mnt/Games/SteamLibrary/steamapps/common/Proton 4.2/dist/lib/wine/steam2.dll.so: cannot open shared object file: No such file or directory
I think this game needs steam2.dll.so, this has caused problems in other games as well, see the references below.
System Information
Retest Compatibility Report
Game works out of the box and is playable now, there is two remaining minor issues (same issues as with developers other game Beekyr Reloaded):
proton 4.2x1 2019-04PULSE_LATENCY_MSEC=60 %command%x1 2020-03steam2.dllx1 2019-04
Compatibility Report
System Information
Distro: Linux Mint 19.1 Tessa (64 bit)
GPU: Vega 56
Driver/LLVM version: Mesa 19.1.0-devel/9.0.0
Kernel version: 5.0.10-050010-lowlatency
Proton version: 4.2-3
I confirm:
steam-357890.log
system_info.txt
Symptoms
Launching the game there is a black screen and nothing happens. Exactly like with the developers other game Beekyr Reloaded #2561
A quick look at the log I could not spot any obvious cause. The game uses Adobe air and has .swf files so suspecting something related to that goes wrong.
Reproduction
Just launch the game