Great composition, orchestration
I liked how this piece started out with a strong theme and developed in throughout the first few minutes. The piece always seemed to be going somewhere and didn't get boring or repetitive.
The build-up at 4:15 creates a good sense of anticipation after the interlude, and I think that you might consider revisiting the main theme more thoroughly and triumphantly at the end to complete the journey. I also think that the piece might take on a greater sense of grandeur if you incorporated some of the lower-registered instruments like the contrabass to fill out the sound.
Overall, though, I think you did a great job and I really enjoyed the piece. Your score must have been pretty ugly.