So I've been playing this game fine for weeks. Suddenly today though, when I tried to play it, it would only displayed the game in a small portion of the screen that's the exact size of the resolution I'm playing at, with black filling the rest of my monitor like a frame. I don't know why this changed, as I don't think I altered any settings. I tried restarting the game, Steam, and my computer, and nothing seems to change. It's definitely set to full screen and not windowed, and I've tried switching between those to get it to work, but no luck. If I run the game at the native resolution of my monitor, then it displays properly. However, I have a really high resolution monitor (2800x1880) and I can't play it at that resolution at a reasonable frame rate. I just want it to go back how it was. As I mentioned, it was working fine for weeks and I have no idea why it suddenly changed. Can anyone help?