

Works perfectly out of the box

Works fine.
Game crashes with Alt-Tab on Linux Mint. And I couldn't get mods to work.
Worked out of the box
Crashes when pressing the quit button to leave the game
Work's OOTB

Good
Can even install mods with r2modman (which has a native linux version)

Every bug i encountered appeared to have also occured on my friend's PC (running windows) too.

Breaks after every launch and requires deleting files to play again. You also have to redo all your settings each launch.
Unable to relaunch game. Requires reinstalling or deleting save data to launch again, every time.
Devs have no interest in fixing.
https://steamcommunity.com/app/1557740/discussions/0/4360120846408198606/

PROTON_USE_WINED3D11=1 %command%
Works fine once you add the argument, crashes when you close it but that isn't an issue.
Works as expected
I haven't come across any issues.

Great
Works out of the box

Occasional crackling at times, but most of the time audio works as expected
Multiplayer connection was flawless.

Slightly crappy networking. Getting hit when you shoudn't sort of problems.
Based off my friend's experience it seems to just be how the game servers are though.
Works absolutely fine. r2modman and mods worked too

Modding also technically works, however, I was not able to get r2modman to work with the flatpak version of steam, so I had to manually move the mod files from r2modmans directory to the game directory.
I had to reinstall the game after full-screen mode, the game was collapsing all the time

Works perfectly with just one click.
Was able to drag mouse pointer out of fullscreen.
The fullscreen issue wasn't a huge deal either way, as I only found myself dragging off screen one or twice.
Used proton experimental, and works fine now!
Might be a difficult experience on controller, but the game is a better experience with keyboard and mouse on any OS
Only present in character customization screen; Mouse was workable but buggy, controller was unusable for customization
at first, launching through r2modman simply did not work - I wouldn't use the launch options it suggests! at the advice of a discord user, I added the empty file .forceproton to the game's launch directory, and it is now working perfectly!
Worked just as well as windows, used Rounds With Friends mod
A few mod manager issues fixed by some tinkering, but plays just as expected with keyboard and mouse

I cannot recommend this without functional local play.
As other have said, only one controller can be connected.
I'm pretty sure this the crashes were caused by mods.
The RoundsWithFriends mod works correctly. The vanilla lobby seems to work as well.
If you want to mod your game, r2modman worked out of the box for me. If you have performance issues, consider installing and configuring the Performance_Improvements mod. My Xbox One controller worked flawlessly for online play.
gamemoderun %command%
gamemoderun %command%
No issues playing the game with friends that I have experienced.
XBox controlers do not work with this game. Many gamepad configuration options were tried none seem to do anything.
With no cotroler support and no multiple players on single keyboard this game is not playable.

Only first controller in steam ordering works, regardless of type of controller. Forcing steam input off allows SOME other controllers to work.
Unless using an offbrand controller with Steam Input Disabled, only the first controller in the ordering works. Local multiplayer is a no go.
Two controllers connected via USB hub. Game would not recognize second controller. Changing order of controllers in Steam menu changed which controller was working, but we could not get two controllers working at the same time.
Failed to launch until I set it to Glorious Eggroll and launched it. Then I set it back to default proton and it launched.
Could not get the game to recognize both controllers at the same time.

Runs perfectly out of the box on the Deck.
PROTON_USE_WINED3D11=1 %command%
Without the launch option it is playable, but on some backdrops it drops to ~40fps no matter how good your PC is. If you add the launch option it runs great in all scenarios.
WINE_FULLSCREEN_FSR=1 gamemoderun %command%
Had No Issues
Plug And Play
Runs well, easy on the battery too.

Works best with proton experimental
Runs perfectly, no tinkering required, modding worked just fine
Multiplayer works flawlessly

Working enough to enjoy on the couch or over the net with a friend. The netcode is a little flaky so lower latency fights will be preferred.
Using keyboard and mouse because Xbox One Controller's left+right arrows corresponded to down+up for some reason. Turning off Xbox Controller Support in Steam just made the game not respond to controller input at all.
2080ti, 3900x can only get maybe 30fps max. Good enough to play with friends but not very competitively. Often drops to <15fps once things get exciting.
The game DOES NOT like being alt-tabbed out of. I have to fight with it in my window manager to try and tab back in before it instantly tabs me back out requiring maybe 40 seconds of screwing about. Super fun to play, but can't alt-tab out just to change music real quick between a round without getting locked out of its window.