

Cap at 40 for at least 1:20!
Significant framedrops when ammount of enemies is high. After 30 min session, constant half a sec freezes

set gyro controls to aiming down sights button (playing docked with steam controller)
Turning down grass density and distance is a must, most settings besides those and render scale do not have an immediate effect. When not busy, game will run on the deck at 40 fps docked with no setting changes, but when there's foliage or busy enemies, it will drop down.
render scale at 50 runs at 60 fps when it's not busy, and in very frantic fights goes down to 40. Turning the render scale down further than that will likely help but at an increased visual cost.
Also as an aside: game doesn't seem to remember settings changes so you'll have to change things each times you enter it, including setting the screen size to 1280 x 800 and turning down graphics and any control changes. It's early access so I assume this will not be true forever.
Personally struggled to aim well with a steam controller but I assume with some tinkering someone will find a good control layout better than I can.

PROTON_USE_WINED3D=1 %command%.
Runs slow outside of wine mode, sometimes there are huge slowdowns that come and go
Major graphical bug while on lobby (Circle with atmosphere texture around the character). On first level: Dying too early can get you stuck in a room. Sometimes character falls out of pod.
Was able to play it by reinstalling steam and disconnecting external HD, still have mostly minor bugs and issues but otherwise its still very enjoyable.

FPS drops in huge crowds of enemies.
Crashed once during 8h session.
Sometimes objectives may fall under the map.
Host crashed once - it disconnects clients after ~10-20 sec

Game ran on heroic launcher, then crashes everytime i try to host a session
It wont run on steam and even on heroic most buttons are unresponsive

Pretty cool game just wanted to add a report to show that it's working as intended on linux with proton and you shouldn't shy away from picking it up

The game originally launched in fullscreen, with everything zoomed in a bit too much and off to the side, so that I couldn't even see the menu options to open settings. However, taking a screenshot seemed to reset this and the game then displayed as intended (so I'm not sure if the problem was with proton or with my system). I then set the game to windowed mode, which persisted on the next launch. While running in windowed mode, everything was fine.
After the windowing weirdness was taken care of, the game ran with no detectable issues.

Works out of the box

I use GE Proton as a preference. I have no reason to believe it is required though.