Since the game is quite old already (but still massively fun!) and most
monitors now are wide-screen, its quite nice when you can use your
default resolution.
This can be done (Wohoo) here how:
When you do this there a path to the exe in the text box. To customize your resolution put this after the last double quote:
-CustomResolution:enabled -r1920x1200x32
(with your resolution there of course)
To play in windowed mode, add this after the double quote: -w
If you don't want the intro (the movie) you can put this behind it also: -intro:off
Run the command to test it, then save the command to the programs menu and use the command to play the game from now on.