In-game resolution settings only capped at 1360x768 and sometimes shows blank option on fullscreen mode.
Saving the settings also doesn't change the resolution.

Right Click Soulworker on Steam Library -> Properties -> Local Files -> Click Browse...


 
Scroll down until you find Soulworker.exe, Right click on it and Choose Properties


 
Click the Compatibility tab -> Change high DPI settings -> Check both boxes -> Ok
 
Click Apply -> Ok


in the Soulworker directory, find General.ini and open with any text editor (notepad / Notepad++)
Change the WIDTH and HEIGHT to your screen resolution. (mine is 1920x1080)
Change the SCREENMODE to 1. (0 = Windowed mode, 1 = Entire Screen, 2 = Full Screen)
Save the changes (Ctrl + S)


 
Launch the game from Steam Library.

You can change the resolution with Option.exe on Soulworker's directory, but in my case the Option.exe wouldn't launch, therefore i'm using the above steps to fix the resolution. Maybe some of you can open the Option.exe and fix your screen resolution with it.