You MUST update ScummVM inside the game package.

The game does NOT work on Linux out of the box. Cyan has totally neglected this game and uses an ancient ScummVM version which is total garbage.

You ONLY have TWO options. The easiest if you have no technical confidence: Set the game's Proton version to "Proton 4.11-13" which is the final version that worked with the game's bundled ScummVM version.

Alternatively, what I prefer: Upgrade the terrible, ancient ScummVM in the game to the newest version.

Here is how to do the upgrade:

1. Download the Windows Zipfile 64-bit from https://www.scummvm.org/downloads/#release
2. Extract all files, and then delete everything (there's a lot of junk files) except the .exe and .dll files.
3. Rename "scummvm-X.X.X.exe" to "scummvm.exe" which is what the game expects.
4. Paste the .exe and .dll files into the game's directory (right click the game in Steam: Manage: Browse Local Files).
5. Set the game to run with the newest GE-Proton or whatever you prefer.
6. Set the launch options to the following, to fix the crackling audio:

PULSE_LATENCY_MSEC=50 %command%

This is not a 3D game, so you don't need any DXVK variables and stuff like that. All you need is what I just said.

Enjoy!

PS: Remember to never click "Verify Local Files" in Steam, because then it will reinstall the ancient ScummVM version. ;)