When BB was first ever shown, with actual gameplay...
In the trailer, there was the prototype version for Under Heaven Destruction, which would've apparently served as a main theme.
I now realize this:
It sounds more metal than the version we have now. D:
That, and I liked the fact that the barrier gauge had an indicator next to it, but no Libra Gauge would've screwed things around.
And certain special effects looked... well... different.
Not to sound like a total nostalgia geek or anything, but the prototype's cosmetics were pretty badass. Personal taste, I know.
I doubt there'd be some sort of Proto Theme DLC, but whatever, it looked awesome then, and the end results still look awesome since the official arcade release.
But seriously, we have to do something about UHD sounding more metal.
I need to play the guitar again. x_x