

Works great out of the box with default Proton!
The game with no issues.

force_vk_vendor="-1" %command%
Few longer stutters here and there but mostly fine
On a couple of occasions, the descriptions/tutorials of some power-ups would not switch off regardless of the buttons pressed, while the game continued normally underneath. Both times I had to load the last save. Personally, however, I believe this is not so much a problem with Proton as with the game itself.
Sometimes UI elements like dialog boxes or even the entire pause menu get stuck on screen until the game is restarted, which technically doesn't prevent playing the game, but can severely limit visibility.
Works fine out of the box

Finished the game on linux with no problems.

100% flawless
I beat the game without ever experiencing so much as a stutter. Enable gamemode if your screen turns off due to keyboard/mouse inactivity.

A handful of the game's UI fonts seem to scale incredibly low-res at the Deck's 800p resolution, but nothing that makes the game unplayable. Namely the charge number in the top left, and the titles when entering an area are lower resolution than what I saw on my desktop.
No performance issues whatsoever, you can even raise the cap up to 90 FPS if you want the camera to feel smoother at the cost of battery (around 14-15 watts). A small handful of the game's text seem to scale themselves incredibly low-res compared to other elements of the UI, but they're not super important either.
Played start to finish with no issues or tweaks
Runs without any issues, just like on windows. Great game.

Runs perfectly
Beefy lagspike upon starting a new game or loading file, runs fine otherwise

Works just like it's intended.
i'm not sure what changed between this report and my last report, actually. i think something was broken with my NVIDIA driver install before, and i fixed at least some of that issue i think? (and seeing as previous "fatal error!" reports seem to be from non-nvidia users i suspect that might be part of it) but upon checking steam system info it looked like it didn't detect my NVIDIA card? mysterious. for posterity i will provide my NVIDIA card (NVIDIA GeForce RTX 4060 Max-Q / Mobile) and driver (525.147.05-7~deb12u1)
Works perfectly out of the box

enable the Give Sybil Pants setting if you want the "playing with other people in the room" feature
Works OOTB

Runs perfectly fine out of the box!
Runs without any bugs, crashes or performance problems with proton 8.0-5
Works great with Proton Experimental on a fresh install. No issues I didn't notice on Windows.

good game runs like expected

force_vk_vendor="-1" %command%
The game was refusing to launch for me with Intel Graphics, until I figured out it works with force_vk_vendor="-1"
nvidia-offload %command%

force_vk_vendor="-1" %command%
If you're playing using Intel graphics, you need the force_vk_vendor="-1" for the game to actually launch. Once it launches, it seems to run fine
The game runs great. There is a bit of screentearing, but I don't think thats a Proton issue.
The game ran great. It had a bit of screentearing, but I don't *think* that it's a Proton issue.

Runs great with default everything on steam deck.

Game crashes once every few minutes after clearing the first boss
I could not get the game to run on any combination of Proton version and/or GPU (Intel/nvidia) for Steam installed through snap. Uninstalling snap version of Steam and installing it through .deb downloaded from Steam site fixed it for me.
In most cases, the game ran perfectly, however on occasion the steamdeck's controller would not be properly recognised, often after switching from docked using a wireless controller, only accepting mouse input via the trackpad. Double checking and fixing the controller order usually fixed it (The steam deck's controller would often be listed as number 2 in controller order, dispite no other controllers being attachted at the time), Otherwise relaunching the game until it resolved itself was necessary.

Some texts aren't correctly displayed
Runs perfectly, even at fixed 90fps with the OLED model (at least if you keep the retro scaling), it just sips battery but that's all.
a "Fatal Error!" popup appears, then the game closes out.

No issues. Game works flawlessly.

gamemoderun %command%
Not sure what issues other people were running into but for me with an AMD GPU under KDE wayland it worked perfectly.
"Fatal Error!" popup appears, closes out.

Fatal error
Game crashes on startup, with a "Fatal Error!" window in the middle of the screen. Tried every single possible proton version, I get the same error.