Go to %APPDATA%..\Local\CartelTycoon\Saved\Config\WindowsNoEditor and delete GameUserSettings.ini and Settings.ini from the folder, and start the game again.
You can also change the resolution in the game settings manually.
If you can’t navigate to Settings in-game, you can do it through the files:
- Find and open the Settings.ini file (for most players, it is on this path
- Change the "r.setres=" parameter according to your screen's resolution. For example, at a resolution of 1920x1080, it should look like r.setres=1920x1080wf
- Save the changes and start the game.