During the intro, hit F5 and you'll be taken to the soundtest. To start the music, you normally have to press Space (as it says on the screen). But before pressing that key, type M, A, R, I, N, A. You'll hear a sound if entered correctly and now you'll have extra music information after pressing Space. To play a hidden minigame, after typing MARINA, don't press Space and instead type M, A, I, T, A, K, A, I. You'll be automatically taken to the hidden minigame. Press Return (Enter) to start the game.