If the game looks like it's stuck on the load screen upon startup, then close out of the game, open Game.ini with a text editor, and change Fullscreen=0 to Fullscreen=1.

The game only appears to be stuck. If you press Z shortly after the load screen appears, you'll see that the game is running normally and that the stuck load screen is just a graphical bug. Loading the game in fullscreen mode appears to fix this.