Eh... a couple mistakes.
At 00:27-00:31, you had a perfect epic transition, and you blew it! At 00:31, you should have come out powerful, but instead you went to a gradual increase in power, which completely destroyed the epic transition. I could note other points in the song, but your main problem is your power, because you're lacking! At 01:59, you nailed the transition, which was good. Now that I think about it, maybe one of your problems is the fact that you have too many epic transitions, and not enough power to back them up.
Now, this doesn't mean that you didn't do a good job, just that you could have done much better. This IS just a demo, so you can still correct your mistakes. I also loved the fact that the song looped, which, for this song, is awesome.
All in all, keep perfecting this song. It has the potential to be awesome, but you'll have to put in some more effort. 8/10, 4/5, and tons of support. Now go kick some butt!