Try to see if there is an options.ini file or settings.ini file in the game dir and change the res there.
Also some of the games have a reset settings exe like hitman for instance...
If none is optional lower the desktop res and try then.
[Edited by kingkob, 12/12/2013 10:52:57 PM]
I'm on a Mac as well, if that affects the answer.
Those are unfortunately not available for options.
I did try lowering the desktop resolution. It did nothing for me.