Not really. The only thing to do with the minigames is get better at them and to learn your limits. If you REALLY want to see the special video, you might as well just buy the second game. There's not much purpose to the secret ending outside of supporting KHII.

If you live somewhere that isn't NA or Japan, then you'll just have to wait.

Alternatively, I suggest YouTube or FileFront (which the last time I checked was down for maintenence), and search for the secret video. If you have Dial-Up, well, that's too bad.