It sorta is a prototype, but not really.

You can play the demo in Dolphin by taking out the .TGC file (that has the demo files inside) from the GCM, then converting said TGC file to a GCM and playing it. I should know, I had this for about a year. :P

The only interesting thing about it from my point of view is that they threw in a symbol list that wasn't in the final releases.