The PC version of Final Fantasy XIII was not a particularly good port, in part because it offered no option to adjust the graphics. In November, Square Enix promised to address that shortcoming with a patch that would be rolled out at the beginning of December, and while I think it's fair to say that the "beginning" of the month has passed us by, the update is on its way.
"As mentioned recently, the Final Fantasy XIII team have been working hard to improve your experience on Steam and we're happy to announce that custom resolutions (720p, 1080p...) and graphic options will be added to the game from December 11th 2014!" the publisher excitedly announced on Steam.
If that date sounds familiar, it's likely because that's also the day that that Final Fantasy XIII-2 comes to Steam. Luckily for us, that one will offer selectable resolutions and run at 60 fps right out of the box.