I've tried replicating the issue on my steam deck, here's what happened:
- I've installed Feyna's Quest through the Itch Linux Desktop App
- I started it through the itch app (while in desktop mode)
- The screen started to flicker rapidly, The mouse snapped back to the center of the screen
- I could still see my desktop, and tried shutting the down through the application launcher menu, which didnt seem to work
- I ultimately shut down the device by opening the konsole and typing in shutdown
- The deck boots back up normally, though it did show a screen of "verifying installation" (which sometimes happens if it's not shut down correctly)
All in all, it's fine now but the game doesn't start properly and produces this visual problem on my end