For what it's worth, I was unable to reproduce this issue. It sounds like this might be an issue with your setup, maybe post the game's Player.log?
@Guy1524 thanks mate! Doesn't look like a player.log is being generated.
❯ find ~/ -type f -iname "Player.log"
/home/bcarr/.local/share/Steam/steamapps/compatdata/392260/pfx/drive_c/users/steamuser/AppData/LocalLow/Spellbind Studios/Rogue Wizards/Player.log
/home/bcarr/.config/unity3d/Editor/Player.log
/home/bcarr/.config/unity3d/Fourfold Games/Xenomarine/Player.log
/home/bcarr/.config/unity3d/Finji/Overland/Player.log
/home/bcarr/.config/unity3d/noio/Kingdom/Player.log
/home/bcarr/.config/unity3d/FerretDev.Org/Demon/Player.log
/home/bcarr/.config/unity3d/Player.log
/home/bcarr/.config/unity3d/AtomTeam/Atom/Player.log
The Player.log instances in unity3d/ and unity3d/Editor/ are both for a different game.
proton 5.0-9x1 2020-09actxprxy.dllx1 2020-09advapi32.dllx1 2020-09gdi32.dllx1 2020-09hid.dllx1 2020-09imm32.dllx1 2020-09kernel32.dllx1 2020-09kernelbase.dllx1 2020-09msvcrt.dllx1 2020-09ole32.dllx1 2020-09oleaut32.dllx1 2020-09rpcrt4.dllx1 2020-09sechost.dllx1 2020-09setupapi.dllx1 2020-09shcore.dllx1 2020-09shell32.dllx1 2020-09
Compatibility Report
System Information
I confirm:
Proton log
Symptoms
The game appears to be running because Steam's "PLAY" button turns into a "STOP" button, but no game window is opened.
Reproduction