When I was pressing random keys I also tried clicking with the mouse (inside the window). It did nothing. Pressing the right mouse button brings up a menu (Mute, Skip, Auto-Play, etc). I pressed restart, enlarged the window, hiding/un-hiding interface and, finally, I tried saving and loading. The latter seemed to have done something as music kicked as soon as it loaded and the regular interface showed up. Though the first time I did this I still couldn't do anything. I tried a second time and the game finally started to work...? Kind of?
Needless to say I don't think this is how the game is supposed to start... ^^;
If you need any more information just ask! :)