Hello everyone. The aspect ratio of 21:9 or wider is not properly supported in this game. When choosing a widescreen resolution, black stripes remain on all sides and it is impossible to play like this.
But you can fix it and run the game in a 21:9 aspect ratio.
How to enable 21:9 mode (or wider)
Here is the steps:
1) Go to this link: https://github.com/RoseTheFlower/UltrawideIndex/releases/tag/thequarry
2) Download The.Quarry.Ultrawide.v1.0.zip
3) Unpack archive anywhere you want
4) Start the game
5) Open The Quarry Ultrawide v1.0.exe
6) Press F9 to enable or disable ultrawide mode.