fPSA: The validation server, as well as the game download server, are both down. These are two separate servers hosted by the same server farm, so my guess is that the farm is having some issue. We're waiting to resolve it. In the meantime: if you launch the game and get only the music, but no window, leave it open. After a couple of minutes you should (if I understand the issue correctly) get the "Main Menu" announcement and be able to interact with the game—it's just taking that long for the server request to time out. This will be addressed in our next update. Alternatively, you should be able to launch the game without an internet connection, if you've already validated.
If you need to validate your game for any reason, sadly you'll need to wait until the server is up. We're so sorry for this inconvenience.
Edit: For those wondering why the game cares if the server is up—the game always checks to see if your game is validated, that way if we ever have to shut off an account that has been pirated, as we've had to do twice now, those players lose their ability to play. However, if it can't reach the server, it will fall back on the last successful check-in. However, this request currently takes a couple of minutes to time out if the server is simply non-responsive. Also, the game needs to be connected to the internet to handle on-demand translation.