Here's an older thread about the same disc:

http://forums.hidden-palace.org/viewtopic.php?p=8775

I'm not familiar with Gamecube emulation so I really can't elaborate on what they said, hopefully you get something from it. Apparently it's not a beta, just a demo. It was released in the same month as the full version, so it's final code. Seems that the preview videos and images are the most interesting part.