

I capped the game at 40 FPS to save battery
Thanks to another player I got the game stabilized by adding launch options: PROTON_NO_FSYNC=1 DXVK_FRAME_RATE=60 taskset -c 0-3 %command%
the proton_no_fsync=1 was crucial to me getting past a save point early in the game in the flytrap mission.
DXVK_FRAME_RATE=60 taskset -c 0-7 %command%
Some texture issues on the tendrils when consuming, everything else was perfect
3-4 crashes throughout the entire 100% playthrough. The game autosaves frequently so not much progress is lost if it does crash.
Thanks to the Linux commenters below for the startup command to get this working.
Played through to 100% completion, though I would only recommend if you are very determined to play this on steam deck.
Does not launch for me whatsoever. Tried every avaliable proton version to no avail. Shame.
Tried every possible proton version
Does not launch/crashes on startup.
You start off with lower resolution and settings when starting for the first time, but max settings at 800p won't hold a stable 60 fps (floats between 50-60 a bit when much happens on-screen), either lower the fps-limit (like 40 or 50) or lower the settings. Didn't crash once for me.

Works great but you need a compatible version. My "Prototype 2 + Radnet Retail (RU)" Steam cd key was not working, black screen on start & crash. I removed it from my account and took the game directly from Steam. It's a different package and this one is working without any issue

Tested wiith proton GE 7-14 & 7-15 & experimental. Starts, black screen for a frame & crash
Has crashed a few times when alot is going on. Most have been after using the first special mass ability. Game auto saves really well so worst case, redoing part of a mission.