Oh poo I didn't think to check resolution changes... there are a couple different ways to achieve that in NWJS, and iirc some have been/are being deprecated. I'll have to poke around, thank you again for troubleshooting!
Viewing post in Hitches every few seconds in Linux (Manjaro 64-bit)
Looks like the resolution issue may be exclusive to Manjaro - I just tested this in Ubuntu and had another person test in Fedora, and no issues there. Maybe you can try completely clearing it out and starting over, or maybe try NWJS v0.51.2? You also might try an SDK version (for example: "nwjs-sdk-v0.52.0-linux-x64.tar").
I tried uninstalling and reinstalling the game from the itch.io app, and redoing the steps above with NWJS 0.51.2 and then with the SDK version of 0.52 - same result unfortunately.
I wonder what's different about our setups besides the base OS? Manjaro is rolling release so I'm running GNOME 3.38.4, Nvidia binary drivers 460.56, kernel 5.11.2.
Yes, I am using X. Wayland is the newer, much more modern display server (drawing and managing windows, handling input, etc) that isn't supported by Nvidia yet, I'd be running it if I could. Most Linux distros do not enable it by default because of various compatibility issues (though the hope is that will change in the next couple years). If I had to guess I'd say a majority of people running Linux games they bought on itch or Steam are still using X.
One thing I was able to do is edit package.json to change the starting size of the window to 1920x1080 (my monitor's native res). This gives me a 3x scaled (1440x810), centered view when the window is maximized, which while not ideal is just about good enough to be playable. That result is obviously pretty different from what you'd get setting the resolution from within the game's code, but maybe that's a starting point for troubleshooting if more players report this issue. (and if not, great!)
Thanks so much for the help troubleshooting!