

You'd never know it's not native
Completed the game with zero issues, all cutscenes play fine as well.
Works out of the box.
There was one time in the computer level that felt a bit laggy, but I had jumped into a specific spot and all the enemies loaded up at once or something. I am not sure if it is related to the game itself or something else.
Everything plays out like it was designed to do.
Have fun =)

Works out of the box, not a steady 60 during action sequences but definitely sits above 30.
Steam Deck Settings
- Refresh Rate - 40Hz
- Half Rate Shading - On
- Manual GPU Clock Control - 400MHz (Could be lower? Could be higher? 200MHz seemed to work on the first level but uncertain about the rest...)
Concluding Notes
The game works perfectly fine out of the box and can achieve 60 FPS during quiet segments with no enemies. However, whenever enemies are around, the FPS drops to somewhere between 40-50.
Adjustments to the GPU Clock Control seems to have helped ease the frame loss but active gameplay will see the frames dropped, probably best to set refresh rate to 40/50Hz and lower resolution as far as it can go.
It should be noted that Inzane difficulty has the highest enemy density of all four difficulties and, as such, will result in heavy frame losses, it's perhaps best to drop the frame cap to 30 on 60Hz mode when attempting to play through the aforementioned difficulty.

Works out of the box
Works perfectly out of the box on every Proton version tested (Default, Experimental & GE)

Demo seems to run fine out of the box with only a minor graphical bug
On boot-up and when switching between the main menu and gameplay, a magenta screen appears. Most likely a missing loading screen texture? This screen will eventually disappear.