After installing The White March, the app appears to be having so problems drawing to the screen. When I launch it, it takes an absurd amount of time to load, just a black screen with a floating menu bar and a spinning cursor. When that finishes, I get a blank screen and a standard game cursor, but I can still hear the music in the background. However, if I bring up the force-quite menu, I am able to drag that window across the screen to, which draws in the missing game graphics behind it. But the screen only refreshes when the window passes over it. I tried taking a screen shot to show you what I mean, but the screenshot actually shows the completely drawn screen, so I took a picture of my screen with my phone to show you.

Reboot your computer.

No change. The screen still won't draw, and the game is unplayable.

The game seems to work fine in Windowed mode, but only at a smaller resolution than my monitor. Not ideal, obviously.

What are your system specs., because it sounds like you don't meet the minimum requirements, graphically at least?

That would be quite bizarre behavior for an underpowered GPU - it's not impossible tho.

Anyway, I would suspect corrupted files or emerging hardware issues.

Corrupted files?
The question at hand is which files? I'd start with reinstalling my GPU drivers, then the game, then entire bloody operating system (and yes, none of these are guaranteed to help.)

Hardware issues?
How old is your computer? Did you ever notice wierd graphical glitches in other games? Isn't your GPU overheating? (I've seen the weirdest shit on an overheating GPU)

All of these are shots in the dark tho, you might also consider asking on Obsidian discussion boards

First, so you know, I'm running this on an iMac with OS X 10.11. My iMac is from late 2013, but it was pretty high-end for an iMac. My specs are:

3.5 GHz Intel Core i7 (quad core)
24 GB 1600 MHz DDR3 RAM
NVIDIA GeForce GTX 780M 4096 MB

Not super high-end by gaming PC standards, but more than capable of running this game (waaaay more). In fact, it ran great before I installed The White March.