Sounds good!
Nice progression throughout the piece and builds very naturally. A great showing of knowing when to use the brass. Also impressed with Musescores sound quality, though not perfect it's way better than many other notation programs.
My biggest gripe is the ending. I think for this jam and my approach to rating the challenge aspect it comes down to not only including separate sections but also how they are used. I think the outro seems a bit unfulfilling, and personally, a fade out can be a bit cheap, especially after such an epic climax.
But overall I like it!