
By default the game will launch in a very weird and low resolution and it won't register the press of the B button, so you can't change resolution in game with Proton Experimental, 9, 8 or 7 because changing resolution required a B button press to confirm your edit in the Options menu.
To fix the resolution on the Steam Deck you can download Proton 4.11, set the game to run with Proton 4.11 and this will allow you to correctly launch the game with the B button working, go into the Options and change the display mode to either Windowed or Borderless Fullscreen, press B to back out of the Options, doing so will save your display settings and then you'll be able to properly launch the game with higher versions of Proton, like Proton 9 with both a working resolution and a working B button.
Set feamerate to 40
Very weird initial resolution, fixed by launching the game in Proton 4.11 to tweak the Graphics settings and then going back to Proton 9.

Plays without a hitch
Played the whole game without any linux-related issue. Beware that you are going to see some white flashes while moving the camera, this is an engine related bug and will happen in any platform.
works perfectly

Set native resolution and every graphics setting to medium

I bought the game on gog and installed it in bottles then just added it as a non steam game but not from bottles menu. I tried installing the gog offline installer as a non steam game and got a black screen with nothing that would fix it. Installing it in bottles then adding it by it's exe in steam works using Proton 7.06.
Works great out of the gate!
Works OOTB no tinkering
Seleccionar la opcion "Cargar Partida"(Para que no se "rompa" el juego).
Inicia y funciona: Terminado al 100%, 1080p, graficos(alta), control(xbox one/series), Proton=5.0-10
SOLUCION A LOS ("CRASHEOS"):
Correrlo con la version de Proton=5.0-10(Con otras versiones = se crashea).
En la opcion de los graficos:
- Poner todo en Baja, Medio o Alta(No combinar opciones/Por default, vienen combinados).
- Siempre seleccionar la opcion de "Cargar Partida"(No seleccionar la opcion de "Continuar").

Mapped B to Right Bumper (Dodge), Mapped L4 & R4 to Left Stick Click (Run), Mapped L5 & R5 to B (Interact/Back). Used a Mode Shift when pressing Left Bumper (Power Select) to Change the B Button mapping back to B.
40 hz refresh rate limit

Works great
This worked really well.
gamemoderun %command%
It was sorted out by switching to window mode and then back to fullscreen. It has to be done on each start up which makes it very tedious.
Very enjoyable. Apart from the minor fullscreen issue everything runs perfectly well.
It is possible to switch on any subtitle language while maintaining different dubbing. Just use my modification from NexusMod: https://www.nexusmods.com/darksiders3/mods/3.
Subtitles and menu texts are changed everywhere. Only the first introductory movie remains in the dialogue language :(
Subtitles languages:
- French
- German
- Italian
- Polish
- Spanish
- Russian
Chose your language, and copy pakchunk2-WindowsNoEditor.pak to "...<Game location>\DarksidersIII\Darksiders3\Content\Paks"
A lot of text is very small on the Steam Deck's display.
Wonderful experience!

Crashed twice the entire playthrough.
Works fine, but not my kind of game. Having it installed on an external drive must have been the cause of earlier malfunction.
is there a saving function?
Finished game without issues
I saw only one video with test patterns in the beginning of the game. So mf-install may be a good idea
Alles Top, kein unterschied zu Windows

Yes, i just recommend to expect some rare behavior of the game if you run it with quite old GPU as mine.
5.11-GE-3-MF GloriousEggroll
on some scenes it was usual to desynchronized the audio from the scene.
Some scenes are just weird: frequently aren't all characters on screen (for example, at the final scene of the game), there0s lack of some textures, too. But still, is playable. This may be due that my GPU Laptop is quite old
Runs Great.
Download, install and play.
When you go to the Steam Overlay and you start Youtube in the overlay browser, the game drops under 30 fps, and you've to restart it to solve the issue. Otherwise it runs perfectly smooth.
FPS drops, after using the Steam Overlay browser.
Runs without any problems out of the box

Any Proton version, including experimental, says " running" nothing visible happens, then stops.
Rebooted first, I have the game on an external drive in extra Steam library, this works fine for other titles.
Works out of the box
Performance is pretty decent out of the box, but you'll still need to do some tinkering in order to get a smooth 60 FPS.
Mouse cursor was very laggy in the main menu, but once in the game, controls were snappy and working properly.
Running it at 4k resolution, I couldn't get steady 60 FPS with everything set to Epic
I had to crank most down to High
, while lowering both 'Anti-Aliasing' and 'Post Processing' down to Medium
.
Only then I could run it at a stable 60.
Runs better than I'd expect even from a good native port. Great performance on maxed settings.

Proton-5.8-GE-2-MF GloriousEggroll
Proton-5.8-GE-2-MF
Game worked perfectly out of the box
Played for some hours and it was a very smooth and good experience without fixing something.
The game runs perfectly out of the box; played through the entire game using Steam Controller.
The game always starts windowed, but pressing F11 twice fixes it.
all setting epic less than antialiasing in high to play all time 4K@60fps, only drop 5-6 fps.
make sure to use latest Proton, maybe. ran full game until the end, very much enjoyable! Used F710 with USB Dongle
Few freeze
Worked without any problems besides having to disable my second display, which is a common proton problem for me.
Needed to disable my secondary display.