


As others have pointed out:
- Delete "start.mov" from your game files. This intro will crash your game, and you won't be able to configure this in the game's registry until you have successfully launched the game once, and this will not be the case with the intro in the game files.
- Get proton GE
- Run "protontricks 1478650 d3dcompiler_47" (or if installed via flatpak, use the GUI and select "Install a Windows component" -> d3dcompiler_47)
- If above is done, and you haven't touched the registry, you will start into a black screen. Press space/enter/ESC as if you would skip an intro movie, and the game will load.
Tested on both PC and Steam Deck
ALT + Click is not detected at all (required to make Diggles consume things, like books)
enabling "1478650 d3dcompiler_47" using protontricks and deleting the intro movie from the game files.
Stays on black when starting due to missing intro movie. Waiting/klicking get's to the main menu
Runs great with adjusted controls to fit the inputs of the game
Game did not launch with steamdefault settings. No success either with Proton GE and running "protontricks 1478650 d3dcompiler_47"

Issue with intro movie, I had to remove it from game folder
I had to install Proton-6.14-GE-2
Run
protontricks 1478650 d3dcompiler_47
Removed intro movie
Thats all
Registry was empty until I succesfully started a game
But after that I could modify them
protontricks 1478650 regedit
HKEY_CURRENT_USER/Software/SekOst/Diggles/Misc/ShowFMV=0

d3dcompiler_47, disable intro in registry
https://steamcommunity.com/app/1478650/discussions/0/4993894146666532164/ helped finding the problem ("protontricks 1478650 d3dcompiler_47"). As for the bug with the intro, use "protontricks 1478650 regedit" and disable it like in this post: https://www.gog.com/forum/diggles_the_myth_of_fenris/the_hidden_diggles_settings (this registry is in a sandbox for just this game, so don't worry).

Tried proton 5.13 and 6.1-GE-2
5.13 had a black screen once, 6.1 three times before ultimately crashing

Not working with multiple official and GE proton versions
I tried multiple official and GE proton versions but the game would not even open a window before steam reverts to the "play" button. With suggested 5.21-GE-1 the screen would (at least) switch to black and back three times before steam reverts back to the "play" button.
Crashes immediately after startup

5.21-GE-1 GloriousEggroll
protontricks 1478650 d3dcompiler_47
ALT+TAB kinda breaks the game window at random, further ALT+TABs may bring it back
Since the game uses ALT+KEY combos you will run into trouble if your DE uses those for window manipulation. winecfg -> disable "Allow the window manager to control the windows" under "Graphics"