
gamescope -w 1920 -h 1080 -W 1920 -H 1200 -f -- %command%
Minor artifacts around some objects that look like dead pixels. Very infrequent.
I have a 1920x1200 monitor, and the game would try to scale to it and cropping out parts of the screen. Gamescope managed to fix this. I did have to disable VSync when using gamescope or the game would crash a few minutes into a run.
Mouse sensitivity feels a little weird but that might also be because I'm using a trackball.
When using Gamescope with VSync enabled, the game would crash after a few minutes. Disabling VSync seems to have fixed it.
In my case tinkering was necessary because of the monitor aspect ratio.
While I have reported laggy input, I want to make clear that for the vast majority of the time I have played (44 hours at time of writing this), input has been fine. However, after some prolonged play sessions (and a bit of Steam Overlay and alt-tabbing to make notes), mouse input would sometimes become incredibly laggy. I have to fully close and reopen the game to resolve this issue.
I can't reliably reproduce it, but when alt tabbing sometimes i would be unable to control my camera after coming back to the game. My mouse would work fine in the pause menu, but I could not turn the camera at all without exiting full screen

Cutscenes broken on non-GE proton, but work just fine with GE.

Window would not open. Turned out I needed to select the game icon and press alt+enter.
Game window was not coming up and clicking on the icon in the taskbar was not bringing it up. Turned out I simply needed to press alt+enter to get the window to show up. Working great now!

Unable to open game window
Game launches, but window is not visible or able to be opened. Sound is playing in the background. Tried Proton experimental & 9.2 as well as launch options PROTON_USE_WINED3D=1 %command%

Fun but tough puzzle game
Main screen has some small artifacts, no impact while playing
Currently on Day 32 and aside from some small artifacts in the Main Menu there's no issues while playing the game!
Will need to use Protonup-QT and force compatibility with latest update. Otherwise you will not be able to see the cutscenes.
Works rights out of the box

No issues, extremely good performance.

Absolutely wonderful game, runs acceptably (not flawless) on the deck. Install Proton-GE with ProtonUp-Qt to get cutscenes working.
R1 brings up the room directory, which makes screenshots with Steam + R1 tricky sometimes, so I mapped it to R5.
Locking it to 40-45 FPS gets you ~2 hours of battery life and gets rid of the stutters. Locking it at 30FPS allows you to limit the TDP to 6W and get 3.5-4h of battery.
Some smaller text (including clues) that is readable on a bigger screen/higher resolution is hard to read or even notice on the smaller screen of the Deck.
Playing with ProtonGE lets cutscenes play, but adds coloured pixel artifacts to random edges in the world, and on the main menu's text.
Didn't experience it myself, but currently there's a bug where making a second save file (to try and achievement hunt) can overwrite your first save file. Might not be an issue in the future though!
Dips from 60FPS, no issues locking at 40-45FPS.
The game runs at 60FPS with semi-frequent dips, so I'd recommend locking it to 40-45 FPS to get rid of those dips.
Was not able to install game
Works perfectly

FPS limit to 40
Seems like an interesting game! Looking forward to playing more! Videos wouldn't play with the default Proton version. Switching to GE 9.27 fixed it. I tried experimental like other people suggested but it didn't work either.
The dev seems to be aware of the issue and is trying to fix it.

Fullscreen toggling makes the game 'hang', req. force quit.
Fullscreen seems problematic even under GE.
The way I found to fix it is to start with "PROTON_USE_WINED3D=1 %command%". You can then make enough progress to toggle off fullscreen in Settings->Graphics.
Once you've managed to switch the game into windowed mode, you can exit and restart it without this workaround.

Some suggest videos need experimental or GE to play but I had no issues. I use experimental anyway usually, but I chcked just to make sure.

Like other said, base Proton or Proton Experimental does not show Cutscenes, not only the one at the beggining, need to instal GE-Proton, I tested with the 9.27 and worked perfectly

45fps tdp 10w
a little choppy sometimes

Reached credits without running into any significant issues.
One music track had a noticable static popping in a certain area when it looped. This may not be a linux issue, and happens rarely enough it was completely managable for me.

Requires launch options to start properly
PROTON_USE_WINED3D=1 %command%
Does not make progress unless "PROTON_USE_WINED3D=1 %command%" is used.
Intro video does not play. Hold ESC to skip.
red pixels surrounding some menu item text, bright red/green/blue pixels on some object outlines in game at certain angles/distances

Works Out of the Box
Played for around 2 hours, 4K 120FPS, no issues.
Works out of the box, no tinkering required

40hz refresh rate
Just installed in Steam and launched without issue.
limit fps 40 and tdp to 10

The Steam Verified statement said that there is small text that may be difficult to read. So far, I have not found any text that was difficult to read (alltho I have only played the game for a couple of hours).

Cut scene videos only show a black screen. You can hear the audio, but you can not view anything.
Other than not being able to view the cut scene videos (which, so far, have not prevented me from playing the game, the game plays well on my Chromebook.

Worked perfectly
Everything worked out of the box with no need to tweak any settings

Intro cut-scene requires GE-Proton, everything else seems to work fine