Tutorial images is the only issue
As others have mentioned, the tutorial billboard images don't show up.
The game properly detected my controller ahead of my keyboard, which is rare for a Proton game.
Game seems to run just fine. The sound is good; Menus are responsive, etc. I don't have anyone to test MP with just yet and I'm personally not a big fan of random MP matches. The tutorial section "windows" still appear blank so it may be best to find a tutorial video or just poke around until you're comfortable. Played two matches with bots and the game worked just fine. Haven't had time to play around with different tweaks.
Short test: Needs mentioned tweaks to start, seems playable though, crashes on exit.
Crashes on exit and so minor graphical glitches, otherwise fully playable.
Tutorial "Windows" have no text. Crashes upon exit; must force quit.