When I open the graphics configuration, I am able to change the internal resolution by clicking on the enhancements tab. Under the general tab, there is no option to change the full screen resolution. The resolution looks fine until I put it in full screen it looks blurry. I'm using a MacBook Air. Here are two images to show what options I can see
m.imgur.com/a/tkIBX
m.imgur.com/a/tkIBX