I already know about the res.txt file and added my monitor's native resolution of 2560x1080 to it. While it looks great, the game seems to have issues with such a wide aspect ratio. Namely, Items I'm 'Holding' don't show up on screen, and the console screens are zoomed in too far to see what I'm typing.
 It's only playable if I use a regular resolution and tolerate the image stretching, so I hope there's a fix.