Compatibility Report

• Name of the game with compatibility issues: Penumbra: Requiem
• Steam AppID of the game: 22140

System Information

• Steam Deck: Steam OS Stable Channel v3.4.4
• Driver/LLVM version: 4.6, Mesa 22.2.0 (git-17e5312102)
• Kernel version: 5.13.0-valve36-1-neptune
• Link to full system information report as Gist
• Proton version: 7.0-6 and Experimental

I confirm:

• [X] that I haven't found an existing compatibility report for this game.
• [X] that I have checked whether there are updates for my system available.

steam-22140.log

Symptoms

On Native version: game crashes upon launching the game.
On Proton: Stuck in Intro. You're supposed to stare at a blinking computer until you're knocked out and respawn starting gameplay. But here you're stuck sitting in a pitch black room staring at the computer screen indefinitely.
Plus, not turning off Post Processing Effects results in a pitch black screen in game but turning off PPE results in the lighting becoming nonfunctional.

Reproduction

Launch game. (Get past title screen.)