

Runs how I remember it running on Windows

Persistent stuttering if FPS set to above 60, not sure if this is Proton specific or universal
If you stick to 60 FPS, it plays exactly like Windows. I'm sure regular Proton causes no issues at this point, but GE yields slightly faster load times, so be sure to take note if that's something particularly important to you
Game would not launch unless I ran it under the latest version of ProtonGE. Turned down the settings down to medium and in performance mode for constant 60 FPS.

Like Native never had any issues
Played with 2 different friends at different times and we never had issues with multiplayer either.

prime-run %command%
Occasional crashes during alt-tabs, with roughly 5-10% chance per each alt-tab. Especially frequent when swapping (running something memory-consuming while the game is minimised), but not necessarily. Haven't tried yet, but people down in the other reports have recommended switching to Proton 7. Occurs in both fullscreen and fullscreen borderless (haven't tried windowed mode)
Crashes unfortunately ruin the experience a bit. The game doesn't support saving mid-level, so you'd have to play it again from the very beginning when occurs. Technically you can save mid-level, but only stuff like amount of gems collected, not the level progress.

Runs fine.
There's no option to select other aspect ratios other than 16:9, meaning that on my 1920x1200 monitor the highest I could go was 1920x1080. Not a big deal, only mentioning for the sake of being accurate.
I must also mention that the game, for some unkown reason, absolutely destroys the CPU. 80% util of a 5800X3D. It does reduce after around 10 minutes or so, so I assume it must be shaders compiling of something similar. With that said, I don't know if the game is actually running better than it was a couple of years ago, when I last tested it on Pop_OS, or if my current PC is simply bruteforcing the game to behave.
the only time you would need to drop graphics below medium would be for open world maps

Did not run as well as I feel it should have, but I was able to get it to run at 60 fps
Ran fine after lowering settings. I know I do not have the most recent or up to date hardware but it still performed noticeably worse than on windows. Lowering the settings allowed it to run at 60 fps with very infrequent dips when loading. Did not play too far into the game but I did beat the first two worlds with no problems outside of the performance issues

Optimization config
Would just stop displaying anything if at a specfic resolution and alt tabed as fullscreen.
Nyakuza Metro lag's alot.
had the same problem's as before but overall worked great
laggy at times but overall decent perfomance

Requires switching to a specific Proton version (7.0.6), otherwise you'll experience crashes at startup and random stuttering/freezing
Ingame: medium graphics profile to stay around 60fps

PROTON_USE_WINED3D=1 PROTON_NO_ESYNC=1 %command%
Occasional beefy lagspike upon loading into a level, fixes itself after 1-3 seconds
crashed once during my vanilla playthrough, no idea why, has been perfectly stable otherwise
Achievement detection seems to be wonky, sometimes it just doesnt give you achievements
For the most part its fine, the wonky achievement detection isnt a dealbreaker to me and the lagspikes, while annoying, are functionally just another few seconds of loading screen after the loading screen is over

Didn't launch but I was expecting it (My laptop has borked hybrid graphics and the iGPU has incomplete vulkan support)
"Your video card does not support alpha blending with floading point render targets (D3DFMT_A16B16G16R16F)

Game wont actually fullscreen until clicked on
Dualshock 4 detected as Xbox 360 controller

DXVK_ASYNC=1 VKD3D_FEATURE_LEVEL=12_0 mesa_glthread=true WINEDEBUG=-all __GL_THREADED_OPTIMIZATION=1 PROTON_LOG=1 WINE_DISABLE_VULKAN_OPWR=1 PULSE_LATENCY_MSEC=100 gamemoderun %command%
With Proton versions 9 or above, certain levels - especially Chapter 2 Act 6 - have extreme and frequent stutters that make it difficult to play. With some older Proton versions, this problem is resolved but DLC is not detected. Issues were fixed when steam was set to offline mode. Likely some issues with SteamworksAPI calls.

DXVK_ASYNC=1 VKD3D_FEATURE_LEVEL=12_0 PULSE_LATENCY_MSEC=100 mesa_glthread=true WINEDEBUG=-all __GL_THREADED_OPTIMIZATION=1 PROTON_LOG=0 WINE_DISABLE_VULKAN_OPWR=1 %command%
Trying to re-bind controls softlocks the game. An old bug present on all platforms.
Reducing effects helps a lot
RAM cosumption skyrockets while using several mods from Steam Workshop, may eat all the memory of the system
Used the online mode very little, only enough to get the achievements that force the player to use it (bad achievement design)
One of my favorite games of all time

It works
The game works perfectly I haven't run into any issues with it so far, it's just like playing on Windows.

gamemoderun %command%
I make even the new events with a friend and the online its working all modes like a charm.
The game its running 100% fine with online, mods and everything. Enjoy!

The first time the game was launched, it started with a shader compilation that took about 10 minutes, but subsequent game launches were fast.

slight stutters but overall playable
game ran fine with no real issues vanilla. Could not get workshop mods to work no matter what I tried.

game sometimes outright crashes with mods
mods and dlc WILL NOT be detected without switching to experimental
so uh yeah i guess its fine but still could be better

The game runs out of the box, but it will NOT recognize DLC or mods you might have installed. You have to switch to Proton GE for the game to acknowledge that you have DLCs and mods installed.
60 FPS in the space rig without mods + no online party. Nyakuza's Metro frerroam mode without any other players around was another story, capping at the mid 50s and often dropping to high 40s. Therefore, I locked the FPS to 30. Pretty stable that way.
Mods caused severe performance issues and also made the whole system crash upon attempting to load a level.
Online party works just fine.
Local co-op also works just fine.
For the love of all that's holy, don't bother installing mods. Unless I'm missing something quite significant, the game runs quite badly with mods, which also causes the whole system to crash upon attempting to loading a level. You also cannot play with the default Proton version if you have the DLCs, as the game just won't acknowledge that they're even installed. I switched to Proton GE and seeing the game works with the DLC and without mods, I don't feel like tinkering further. Honestly, I think Valve need to be more meticulous with what they deem verified, cuz A Hat in Time should not have that tag. It should be playable at the very least, but not verified considering the issues listed on this report.

Crashes and also takes Steam with the crash when loading maps
Can only play on Hub, as for loading a level is where it crashes.

The game works just fine with no problems besides not being able to Alt-Tab in fullscreen although an easy workaround exists.
Using Alt-Tab while fullscreened would black out the game window and stop playing audio. The game stopped working. I do note that a fullscreen that does work with Alt-Tab can be achieved by choosing the window-borderless option instead of fullscreen, and choosing the highest resolution.
Works as expected. (I didn't test it for very long though.)

It has weird and unexpected behavior with mouse grabs and detected mouse inputs only on a vertical line of my main display (2x 1080p config, right is mapped as primary). Sometimes it allowed my mouse only to move on that line other times it worked normally other times it didn't run the grab but still only detected on that verical line. I don't know what causes this behavior. Moving the camera with the mouse was however uneffected, only menus and hat switch UI was made annoying. Controller inputs were completly fine, with and without steam input.
I have Proton Experimental set globally as my prefered compatibility layer. I have not tried older versions.

Vulkan shaders could take a while to finish, but after that, it runs perfectly.
Mouse becomes highly sensitive out of nowhere

The game doesn't launch
I tried several different versions of proton. Tried different launch parameters. Tried protontricks. None of that worked

Fps would be finicky if the in-game fps was capped. Uncapping the framerate and capping the Deck's fps to 60 allows for 60fps the majority of the time on Med-Low settings. Never went below 50 through my playthrough.
Used proton experimental for archipelago mod usage. Unaware if performance has changed on regular version. But game performed well when using it a year ago.

Shaders still loading in the background so you can get 25fps until it cache everything, you can disable the cache on the game settings if you want.
frame drops from time to time and stuttering that happens on windows too
I had problems starting up the game, it open on a black screen window and used 100% of the cpu, it can be fixed adding "d3d9.dll" from the DXVK github " https://github.com/doitsujin/dxvk/releases " and the game opened normally. (Thanks to larsimusrex)

Probably works best on Deck capped at 60fps, maybe 75fps. Great experience nonetheless!

2 player co op on steam deck works great, both controllers were registered and worked as expected.
great experience on steam deck, consistent 60fps even on high, with minimal battery drain.

the loading shaders screen on steam stops at 99% and never finishes, skip it
game isnt synced between others but that seems to be the case with everyone.
aside from the shaders loading getting stuck game works perfectly fine, and at least for me im able to skip it when it starts with no issues.

unusual stutterings
Game crashes loading the first stage
Crashed my PC even forcing experimental or GE

Tested with listed GE version and Experimental.
Lokks worjing fine

Just let the game finish the sharders and the game run smooth like it does on Windows