

Starts good
Played with Proton 9.0-4.

The game worked perfectly fine on the GloriousEggroll version of Proton.

Game doesn't run that great honestly. Had to change refresh rate to 50hz and lower quality to have it usually run at a stable framerate.
Game runs WAY worse than it has any right to. This game can run on a potato, so it's just incredibly weird that it's having issues ONLY on the Deck. I'd go so far as to say it shouldn't be verified because of it.

gamemoderun %command%
Use Game Mode to boost the game's performance on weak hardware.

Works fine, triggers Intel Arc GPU timeout bug
There's a handful of games on Intel Arc that trigger some sort of bug in Chromium and break Chromium/Electron apps (black screen, Gecko is unaffected) until the desktop session is restarted. This is one. Be warned.
Log lines along the lines of the following in dmesg
[1306066.529281] Fence expiration time out i915-0000:03:00.0:Xwayland[3996018]:3d2!
[1306079.956584] i915 0000:03:00.0: [drm] GPU HANG: ecode 12:1:85dffffb, in Xwayland [3996018]
[1306079.956590] i915 0000:03:00.0: [drm] Xwayland[3996018] context reset due to GPU hang
it just works out of the box.

No changes or settings are needed. This should be marked as supported.

Worked perfectly
I played with Xbox elite controller, and it worked correctly.
Change graphics from default "highest" to "high", Set 40Hz/40fps
Default graphic options are good for 30+ fps, lowering to "high" settings is pretty stable 40, and works well for 40Hz.
other than one small graphical glitch during the unreal engine intro/logo, the game is perfectly playable
When using Proton 7.0-1, the game is stretched vertically (intro videos are fine) and is unplayable. Proton Experimental works just as well as Proton 6.3-8 however.
Plays perfectly.
Only on the Unreal Engine logo splash. Main game works fine.
Trying to switch to other programs like with ALT+TAB would just keep me stuck in the game.
The game plays pefectly, I have not encountered any sort of bugs or glitches that would've ruined the experience. Game works flawlessly with the Dualsense and Steam Controller.
Did not find any issues
Not a single issue playing through the game with a controller

Lots of dropped frames, some minor tearing and control responsiveness was slow
Tearing and juddering
Slow frame rates, tearing, and juddering
The game works with no issues whatsoever. No tinker needed
I also played it with my cheap Chinese Bluetooth controller, and it worked out of the box.
Works flawlessly with proton 6.3.7
Alt tabbing works. No commands were needed to run. Was locked to 60 fps.

Played with Proton 6.3-7 and option PROTON_USE_WINED3D=1 %command%
Works nice out of the box with some slight stuttering
Slight stuttering here and there. FPS peaked at about 62fps at 1440p ultrawide with dips down into the 30s.
Runs absolutely fine.
Challenging game to play with how the controller moves the snake, great fun worked flawless.
No issues, played with a DS3 controller
Runs good, no issues.

Runs well, only has a minor glitch with fullscreen
I had to toggle fullscreen off and on again every time I launched the game.

Generic Statement That It Doesn't Work
Nothing happens for a while, then a window appears with "Fatal Error"
perfect
The game is slow in high resolutions and quality. But on my hardware it is just the same in windows
No game window appears
System menus overlap the game. Just need to toggle fullscreen off and on again.
Major slowdown
The game suffered from extreme slowdown for me, and felt uncomfortable to play because of it.
No matter the adjusted settings, the game always seemed to run slower than 60 fps. Felt closer to 40 or 50. As such, the game was frustratingly slow to play.
OOTB experience now with Proton 5.0-9, will take 30+ seconds to show window, then runs at 45-55 fps on max settings 1080p
sounds can get a bit stuttery for couple seconds after tabbing out of and back into the game
Tested with Proton 5.0-9 and Proton-5.9-GE-5-ST. Running with Proton GE game will show 2 unskippable intro videos before steam logo appears. Proton 5.0-9 will not show the videos, thus saving you time. Minimizing fullscreen window works better with Proton 5.0-9 as well. screenshot
The controls are unique and a little hard to get used to, but it's a very unique take on a puzzle platformer. I'm enjoying it so far!
Full screen initially didn't overlap the the system menus, but switching full screen off and then on again worked for me.

Platinum rate proton game
For radeon users, set ACO as the main shaders compiler "RADV_PERFTEST=aco %command%"