Relevant entries from log:
fixme:mscoree:parse_supported_runtime sku=L".NETFramework,Version=v4.0" not implemented
warn:module:load_builtin_dll cannot open .so lib for builtin L"Steam2.dll": /home/noxp/.local/share/Steam/steamapps/common/Proton 4.2/dist/lib/wine/steam2.dll.so: Kann die Shared-Object-Datei nicht öffnen: Datei oder Verzeichnis nicht gefunden
warn:module:load_builtin_dll cannot open .so lib for builtin L"Microsoft.Xna.Framework.dll": /home/noxp/.local/share/Steam/steamapps/common/Proton 4.2/dist/lib/wine/microsoft.xna.framework.dll.so: Kann die Shared-Object-Datei nicht öffnen: Datei oder Verzeichnis nicht gefunden
Game also has mentions of System.Windows.form in the log.
This one's XNA3 with Forms and a C++/CLI Scaleform library, so a lot of nasty stuff at once.
This should work now with WINE_MONO_OVERRIDES=Microsoft.Xna.Framework.*,Gac=y set and a build of Wine Mono from the develop branch. https://github.com/madewokherd/wine-mono/actions/runs/1134003630 has a recent build, you can scroll down to find the "make msi output" download, and protontricks can install the msi into the game's prefix.
Compatibility Report
System Information
I confirm:
steam-223730.log
Symptoms
Game doesn't even start. Needs XNA and .Net.
Reproduction
Try to start the game.