

Can't return to game after alt tabbing if game is fullscreened
After some recent updates, the linuxtest beta works totally fine for me on the latest stable version of Proton.
Please see this link for how to opt into the linuxtest beta: https://steamcommunity.com/app/3272360/discussions/0/604158165590757615/?snr=___

Works great on only Windows Machines, Hidden Gem!

Scaling issues really, but once fullscreen button is clicked, it improves
[ONLY ON LINUX/STEAMDECK] A video which was supposed to be playing at intro was actually missing, so was just a black background, so it was hard to miss that it was missing functionality
Each game session starts with no fullscreen, button needs to be pressed at start of each session, easy with hotkey shortcut Alt + Enter
[ONLY ON LINUX/STEAMDECK] Videos like intro don't appear at all, and a missing directx call error occurs when Leaving Bunker
Great Game, Amazing Concept, Hidden gem, but ONLY WORKS ON Windows OS.

It's such an intriguing game, dev will just set to older proton version v5.0-10 as default.
Battery Optimization Tips
Lower Refresh Rate & FPS Cap
- Set the refresh rate to
40Hz
. - Limit FPS to
10--30
for better battery life.
Enable Half-Rate Shading
- Reduces shading quality but significantly saves battery.
Adjust TDP Limit
- Lowering Thermal Power (TDP) Limit to 10W helps extend battery performance.
Disable Wi-Fi & Bluetooth
- Since the game is offline, turning off Wi-Fi & Bluetooth reduces unnecessary power drain.
Optimizing for Text Readability
Game fonts seem pre-rendered as a set of sprites rather than dynamically drawn as vectors.
Optimizing via Steam properties for Text Readability
- Navigate to Properties → General.
- Set "Game Resolution" to
1920x1200
. - Enable "Set internal and external resolution" via toggle for improved scaling.
Optimizing via In-Game settings for Text Readability
There seems to be a button with four arrows beside the save "Data" button which can be clicked to what I believe to be fullscreen or windowed, makes a significant difference too. Toggle each game session, and also keep in mind that the toggle button only works when some game popups are closed/deactivated.
Optimizing via Steamdeck Performance settings
Specific for my recommended resolution above:
- Set Scaling Mode to
"Stretch"
so the screen height scales to fill the Steam Deck display. - Use Scaling Filter set to
"Pixel"
for slightly sharper text.
As of May 2025, each game session doesn't start in Fullscreen by default. Good news is that hotkey [Alt + Enter] does the job.
I think setting a Steam button to hotkey will be fun, I will also add a Community Layout for it under my username, so you can ignore advice below.
Configuring a Button for Fullscreen Toggle in Steam Input
To enable fullscreen toggle with a button press:
- Set the button action to trigger
Alt + Enter
- Assign Subcommand "Enter" alongside
Alt
for additional flexibility. - Pressing this button will conveniently switch between windowed and fullscreen mode.
This allows for seamless fullscreen toggling without manually pressing keys.
Dev has been notified that game works with only two Proton versions, 5.0-10 and 4.2-9. They will be working to set that so that no tinkering is necessary to run the game

Tried Proton versions 6-Experimental and Hotfix, might be a Steamworks Integration issue???
Dev may need to recheck Steamworks API integration/setup, or update the GameMaker Studio (my assumption it was used to make the game) or it could be missing dlls, GameMaker Studio export issue? It seems other games like Undertale or Hotline Miami 2 (also GM studio games) seem to be packaged differently?