I enjoyed this. The intro is pleasantly heroic, and your samples are good. Plenty of potential here!
Some suggestions:
I like how you added instruments slowly throughout the intro. Could you also make it more expressive, maybe getting steadily louder? Some moderately lower strings to round out the sound at the very beginning would also be nice.
Leading up to 1:20, I'd love to hear a humongous crescendo, with a gong or similar instrument sending you... off to the races! And the next section could be AWESOME if you picked up the tempo to twice what it is in the intro. Maybe John Williams' Duel of the Fates would be good inspiration here. This could become the middle section you need, as mak noted.
Then you could end with a slow section reprising the introduction, but with more drama (you sort of do this already, just needs some more gusto).
Just some ideas, maybe you want to move it in a different direction. There's a lot of good stuff here, keep working on it!