Sorry for the delayed review. I've been working.
I really like the ideas found here. I would really try to build some different chord progressions to add some variety and pique more interest. While it was interesting in the beginning where it bellowed up, it got a little tiresome after some time. The trumpet melodies were very nice though. I would try to build some more harmonies using violins. You did use an oboe (or at least what I perceive to be an oboe), but I think the parts could be made even more exciting.
Some tempo variations could help give the idea of a story progression as well. I really wanted it to speed up, but it didn't happen.
Now for the good: the melodies were quite interesting. I liked the stark contrast between the royal sounding trumpet, majestic in nature, with the dark, almost overpowering strings. Nice job on creating the mood. Since this is a stand alone, some sound effects could also come in nicely.
Now don't take my word for everything, since I'm not expert myself. That's just my two cents.