Hello @W73, please add PROTON_LOG=1 %command% to the game's launch options and drag and drop the generated $HOME/steam-$APPID.log into the comment box.
Ok. I will try.
Thanks. Daughter will be happy.
Thanks, for easy reference, this game uses the Yaga game engine which is fairly rare with 5 releases between 2002-2003.
Unfortunately this game seems to be broken on Windows, too, in the exact same way. Apparently the game requires your system to have a CD drive available, see this discussion: https://steamcommunity.com/app/294700/discussions/0/1642042464734212682/
You can actually work around this in Proton, and the game does launch and play! These steps worked for me:
PROTON_DUMP_DEBUG_COMMANDS=1 %command%/tmp/proton_$USER/run winecfgD:.D: in the dialog, choose "Show Advanced", change the Path to /mnt and change the Type to CD-ROM. See screenshot below.Give it a shot! Do note that some other users in the Steam community have reported other problems with the game on Windows. It appears to be pretty buggy :(

Thanks for hint, but i am not able to do find that /tmp on flatpak version of steam.
I was able found that $HOME with steam-294700.log, but not /tmp.
I will investigate that.
Sorry, I have no idea how flatpak works. If you figure it out, I'd be interested to hear what happened.
I am able to run winecfg utility via
$HOME/.var/app/com.valvesoftware.Steam/data/Steam/steamapps/common/Proton 4.11/dist/bin/wine64 winecfg i set it per image, but no success.
I also tried Netherland Language version, it came with different cfg file, but it fails too.
FYI, I've had success with launching the game using GE-Proton10-32. Not sure what the fixes are that it performs but at least its a bit easier than making advanced Wine config changes.
FYI this is solved from a Protonfix in GE-Proton that creates the DOS Device (CD-ROM) drive in the game's prefix.
Link to protonfix:
https://github.com/Open-Wine-Components/umu-protonfixes/blob/master/gamefixes-steam/294700.py
Another Humongous Game has the exact same problem:
Pajama Sam 4: Life Is Rough When You Lose Your Stuff!
Thankfully it also now works via GE-Proton and the same protonfix applied to it.
@kisak-valve is this type of thing in-scope for the devs (Valve/CodeWeavers) to work on since this "bug/anti-cheatish" also exists on Windows?
ge-proton10-32x1 2026-02proton 4.11x1 2019-12PROTON_DUMP_DEBUG_COMMANDS=1x1 2019-12PROTON_LOG=1x1 2019-12
Compatibility Report
System Information
I confirm:
[X] that I haven't found an existing compatibility report for this game.
Found problem with Windows 7/8/10 solved by some Daemon Tools.
[X] that I have checked whether there are updates for my system available.
Symptoms
Does not start.
Found this in app directory . I think it is not related to Proton at all.
Seems to be easily solved. But i am not developer.
Reproduction
Run it.