Great!
The balance on this is great - and I love the effects. You've done a great job mastering this.
However, there are two things I would like to suggest. The first involves panning: I really like the effect you've managed to get by swinging the panning back and forth, but it gets to be almost too much when you bring in your violin. You might want to consider decreasing the amount of the swinging panning there - but don't remove it. Just consider lightening it up a bit.
The second thing is something I think could be added - depending on where you feel you want to go next. I get the feeling that you were just coming up on a strong, inspiring section at the end of this demo. If this is the case, you may want to think about making your bass a little stronger (maybe not right away, but with a fade in). So maybe add some double-bass pizzicatos (I think you already have some pizzicatos there, but they sound like cellos... double bass could just be added to double the cello part for that), and potentially have a nice solid, big bass drum beat in the distant background on the bar... some timpani three-note sixtuplet crescendos leading into those beats would definitely give it a nice, almost subsonic push to it... give it that feeling of a strong heartbeat - and it would give you the potential to bring the song into one of those MASSIVE moments where people's hair stands on end, they get shivers, and are utterly blown away.
I'm not joking when I say this has HUGE potential. I really want to hear this when you're done with it. As it stands... wow. I love this piece. On behalf of Newgrounds and the entire global musical community... I salute you.
10/10, 5/5, DL, Favs.
Power to you, Skippy Fox!