Great
I love the theme with the woodwinds and xylophone that starts this song off and ends it; it definitely gives you the appropriate sense of "oh crap" that ought to accompany the appearance of any huge boss. :) I also love the way the song suddenly picks up energy at 17 seconds to indicate an intense struggle. The only thing that could have made this better, in my opinion, would have been greater development of that initial theme in the main body of the song. Reagrdless, this is awesome.