Repetition isn't a bad thing in music, it's just a matter of how you break up the repetition and make it interesting. I think you've done an okay job at that, although I think that past the halfway point it does need something fresh. Perhaps you could try bringing in a new instrument, a new melody/counter melody, or just switch it to an entire different set of instruments for the hell of it.
Mixing sounds good, although at some parts it sounded a bit overcompressed to me. That said, I work mostly with orchestral so it's probably just a preference thing to me.
Good job so far! Keep it up!
I wish you the best with the competition!
~Phyrnna ^_^