The new version 1.1.0 introduces additional options in the Options menu:
Display Mode: Windowed, Borderless Window, Fullscreen
Resolution Presets: Support for both 16:9 and 16:10 monitors
This should make the game more comfortable to play across a wider range of screens and setups, including ultrawide and Steam Deck.
Open the game, go to Menu → Options, and choose the configuration that best fits your screen.
Thanks again for your feedback! I’m continuing to work on further improvements.