
Game works perfectly out of the box.
I have played the entire game with 4k 60fps and mouse/keyboard. Everything works without any problems, including videos and the achievements.

It's definitely a great game for the deck if you're willing to settle on a lower fps value!
Unfortunately you won't be able to run this one at 60fps unless you're ready to lower the graphics settings significantly, which makes the game look not that great; at least for me. So instead, I opted to set the deck's refresh rate to 40Hz and let the settings as they are (I may have tweaked them a little at first, but I don't remember). Nonetheless, here are the settings that I've used:
- General Detail Level: Custom
- Resolution: 1280x800
- Texture Quality: Medium
- Geometry Detail: Medium
- Shadow Qualiy: Low
- Window Mode: Fullscreen
- Postprocessing: Enabled
- Volumetric Lighting: Enabled
- Post Chromashift: Enabled
- Anisotropic Filtering: 4x
- Vertical Sync: Enabled
- NVIDIA Turbulence: Disabled
At first, I felt like 40fps wasn't enough, but after an hour or so, I got used to it and the experience overall was great for me.
Works perfectly fine.

Out of the box install and play
Installs and plays exactly as expected. No issues. Using Steam Input, my bluetooth connected Stadia controller was recognised, with buttons mapped correctly.

Borked
gamemoderun MANGOHUD=1 %command%
Not even able to reach main menu
Required some thinkering to properly detect PS4 controller.
There are FPS drops, usually games runs above 100 frames, but dips happen often, and can be annoying.
gamemoderun %command%
Works well, design issues notwtithstanding.
40fps cap
Worked perfect
Played through whole game no issues
Good albeit not perfect soulslike game. Looks and plays really well on switch. Natively supports gamepad controls.
Setting the framerate cap to 40 allows for using MEDIUM quality settings across the board (significantly improving game's presentation). Additionally, GPU clock can be set to 1200/1300 MHz to futher lower the power consumption.
It eats a lot of battery to play but it runs great

mesa_glthread=true gamemoderun %command%
Runs very smoothly at 75fps, with no issues at all
Runs out of the box
Detailed QA report: https://gitlab.com/z-ray-entertainment/gamezone/steamplay-qa-testing/-/issues/14
Worked out of the box
I used Proton-6.1-GE-2 (Glorious Eggroll). Everything was perfect.

Proton 6.0-GE-1 GloriousEggroll
Proton 6.0-GE-1

Fallen will rise, but not today. Experimental, 5.13, 5.0-10 - all black screen.
Linux mint 19+
borked

The game works very well out of the box.
I had to upgrade my kernel to version 5.10 because version 5.4 was not starting the game.
Now this plays quite well
I was able to pass 2 bosses and die from the 3rd miserably. No issues noticed.
Monitor completely black
Flawlessly and smooth.

Installed, but didn't start
Steam displayed it as being on, however the game never started.
No really issues OOTB.
To exit the game fully - I did Alt Tab to Steam and clicked STOP
Works out of the box
With Proton 5.13-4 it started to work out of the box for me.
Only issue which remains is that the Game window doesn't close on exit but minimizes. Using the Stop button in the library closes the game.
Works OOTB
Works out of the box with proton 5.13-4
Con la nueva version de Proton 5.13-3 el juego funciona perfecto.

Does not start at all
Game is being reported as running and the process needs to be stopped with the Stop button.

Not starting
It says running inside steam but nothing shows up. Tested with various Proton and Proton GE Versions.

Doesn't start
Tried running the game with various launch options set, KDE system monitor ended up displaying the process is a zombie every single time though
Gra na GOG works, może być DRM-problem?
Proton 5.0.7, Proton 5.6 GE, Proton 5.5 GE is tested. Each times used protontricks --gui for GOG help notes (physx, vc2012,vc2013, tahoma,corefonts) but games wont start.
Steam clients says the game is working, but no window appears and than it crushes in the background

Doesn't even start
There is an error message with Proton 4.11, but nothing happens when trying to start with Proton 5.0.4.