

Works very well.

By default, game stretches vertically to fit 1280 x 800. You can (and probably should) fix this by setting the resolution to 1280 x 720. HOWEVER, you must use the game's built-in video setup tool to do so, as setting it using Steam's resolution tool does not work. No other issues to report, though. Game runs as it should.

Runs better than Windows (not joking)
This is a "press play" play game, movies and music sound great and controller works. Level 1-2 had some rings inside the walls, so I jumped to windows to see if that was a graphical glitch and my gosh, the set-up was crazy, my 170hz monitor was making the game go insane, I attempted Radeon chill at 60fps and Vsync, but the game would just run at 170hz, I needed to set my monitors to 60hz in windows to make it work. Yes, the rings should be there, so it wasn't a glitch. This is a rare gem that legit runs better on Linux.

Works out of the box with Proton 8.0-5

It's fixed now, everything works perfectly fine.

Everything works as intended, I played the game start to finish with all of the special stages. No stutters, no drops.

The game boots to a black screen. Audio plays as normal.
Seems to work without issue when using the latest Proton GE.

Borked
Game won't start at all. Used Proton 7.0-5 Flatpak community build.
Game starts up and controls work but there is only a black screen displayed.
Proton doesn't work, use GE
PROTON_USE_WINED3D=1
protontricks 200940 d3dcompiler_43 d3dx9_43
Title.
On default Proton the game only shows a black screen while sounds are playing in the background.

Black screen
Works great with latest Proton GE version. Default Proton will not work, shows a black screen
With proton doesn't launch, but with ge y can play very good
No funciona si usas proton experimental o 7.0, la pantalla se queda en negro. Esto no pasa con la última versión de Proton y funciona bastante bien

Running the game with GE-Proton7-24 fixes its compatibility issues with no further tinkering.
Game shows a black screen with sound.
Don't care enough to fix it with custom shenanigans. Only workaround is to change configs which is not worth the trouble.
Installed d3dcompiler_43, d3dx9_43, mdx
After installing the listed components using Protontricks, had to restart a couple times before the launch was successful. No problems after that.
Tinker Steps: protontricks Install d3dcompiler_43, d3dx9_43, mdx
There is an optional video setup screen you can select when launching the game.
Without tinkering, the game launces to a black screen and you can hear the game audio.
Couldn't get it working. Tried messing with the graphic settings and proton experimental.
Only a black screen
I think I tried everything, several versions of proton, all the fixes
I tried everything, several different versions of proton, the fixes listed on the proton-page, nothing seemed to work
DXVK_FRAME_RATE=60 %command%
(the first 2 solve video problems,) d3dcompiler_43, d3dx9_43, mdx (not sure what mdx does)
Without the needed steps, video will not appear, and/or it will be uncapped (which the game cannot handle.)
Black screen with sound on vanilla Proton. Using PotonGE 7-20, the game won't launch at all.
Only works with Proton-GE currently.
Using the Steam default, I just get a black screen but sound and controls seem to still function. With Proton GE, the game attempts to start but immediately crashes before anything manages to start or display.

Apenas use o proton-ge
Changed TDP to 3 with no discernable performance issue, you can most likely lower the GPU clock significantly as well
Installs and launches with regular proton but draws only a black screen, however music and inputs work. Glorious Eggroll 7-9 fixes this and I found no issues from playing.
The setup works, but the game only shows a black screen.
Crackling audio during the opening and ending cinematics.
Occasional stuttering during gameplay as well as general sluggishness during both cinematics.
Was unable to start play OOB (black screen issue as seen by other users), but after following the instructions in xerz's report it ran well enough.
Had to set up Protontricks (just following other user's reports), game/video options launch without issues, and the game runs, but plays too fast; about two-ish times faster.
As members like xerz, MOAR GUN, and FetusZero have already pointed out, I had to install Protontricks and run "protontricks 200940 d3dcompiler_43 d3dx9_43" in the Terminal to get the game fully working. Before that, it just loaded a blank screen; the sound worked, and my inputs were being registered, but I couldn't see what I was doing. After that, the game runs just as it does on my Windows partition, no complaints.