Wow, this is great. I was really impressed with mostly the composition, but many other aspects of the song are worthy to be praised. This piece really tells a story, and while the whole "kingdom in distress" setting is a bit generic for orchestral songs like this, you executed in nearly flawlessly. I've seen you post around on the forums a little but I can't believe I haven't heard any of your other songs before :(. Nice work!
So, I'll start with the composition, since that seems to be the song's strongest point. I absolutely love the progression of the melody. The song starts off perfectly with some AWESOME brass chords (especially 0:32), and 0:44 was an absolutely fantastic way of presenting the main melody. The atmosphere is just brilliant, and capitalised wonderfully by the harp entrance that came in later on.
The melody itself is very nice, reminiscent of kingdoms and medieval times and whatnot. Loved the occasional change in time signature such as at around 1:15. Honestly that time signature change was so well executed. The tempo changes made this sound a lot more real and dynamic at the same time, so they were a good call :D.
The instrumentation is also quite nice. The use of all of that brass made for a very regal and knightly sound, very similar to that of my old song "Land of Kings". You know, actually this and Land of Kings have a very similar atmosphere and arrangement, for some reason :P. This one is leagues better though. Anyway, overall, the instrumentation was very fitting for the theme you were going for. I also like the mood change at 1:36 although I feel that you could've given that part a little more work. The mood was that of danger and peril, and I think some high violin trills would help give that section a bit more of a "dangerous" feel to it.
The mixing is quite good. I have a big problem with brass chords because frequency-wise they often end up coming out too heavy in the mid section, causing a lot of clipping and giving me a headache to EQ them right. Here you've got brass chords all over the place and they're playing without any discernible clipping, so great job in that department. The song's mastering is also good.
My complaint here is a mixing problem - I feel that the low end was a little neglected. As the1azn8 said, it feels as though the timpani was the only bassy sound. While the timpanis and timpani rolls certainly gave this song some low end power, I feel that this song is lacking some much needed warmth. Try using more double basses/cellos perhaps, I dunno.
The percussion wasn't very revolutionary but it fit very well with the theme. I like the parts in the intro and outro where the majestic brass plays and then stops to leave some room for timpani rolls. That was an interesting contrast. However, I think snares would fit so well here. East/West Symphonic Orchestra has really nice snares in my opinion and I think they'll do wonders in this song if done correctly!
Regarding the intro, it was great. Starting it with that little chime really helped set the mood and then, as I mentioned before, the contrast between the brass chords and timpani rolls was interesting. From then on the progression was spot on. The ending felt a little too dragged out, perhaps, but other than that I don't really have any complaints with it.
Transitions are smooth and just assist in creating that great progression you've got going. My favourite transitions would probably be the one to the flute solo at 0:44 and the one with the change in time signature at 1:15 - 1:20. Personally I don't really have any gripes with the transitions, and usually I'm fussy with transitions so that's certainly a good sign :3.
All in all, this is a great piece. The theme, instrumentation, composition, atmosphere, transitions, progression, mastering and percussion were all great. A few problems here and there, such as the mixing quirk and the lack of violin trills/snares, but in general I'm really impressed with what you've got here. Good luck in the competition, great work on this song and keep up the good work.