This is happens when the authenticity check fails when the program is launched for the first time. The game has locked itself down and won't let you play because it thinks you are running a pirate copy.

Unfortunately failing the check seems to be pretty common for legit owners of the game and it won't recheck unless you force it to.

Go to the parts shop and type in this code:

IDKFA

After that, return to the title screen and it will recheck the license on your copy. I'm a Linux user and thus I had to go through the check process a couple of times before I passed.

Best of luck and enjoy your game!