Oh my
This is a great one man!
Like hamstercake said, from the darker feeling to the happy, more up beat kind of feeling was excellent. Use of instruments as well. I don't think I've heard a better audio submission before.
It seems like it would be a great track for a silent flash, just the music in it and the animation. I can see it now, and it would be excellent... I wish you good luck in the contest or whatever this is made for... It's great man, keep at it... I have no doubt that you will win.