I just bought the game. When I go to the beta page, I get a unity splash screen and loading bar, and then a login form. I log in, and I get a black screen that says "Desktop Dungeons Loading..." and then the text and logo go away, leaving a plain black screen. I can't click on anything, and waiting several minutes doesn't change it. I've tried it repeatedly, and in a couple of different browsers.
What's going on? I'm using OS X, and the latest version of the Unity webplayer plugin. I've tried Chrome and Safari browsers. I'm happy to provide any more information that might be helpful.