Welcome to YC, Dante!
Don't worry... I did enjoy it.
The piece is written in a style that, at different points, reminded me of one of Mozart's minuets.
Warning: I'm going to get nitpicky.
You make use of many chords, but I'd be cautious about the dissonance that arises. I like the use of time signature changes, especially where the 7/8 is introduced. Listening and watching this piece, I can see that you enjoy more complicated rhythyms. One thing I would do is re-evaluate the rhythyms in this piece. Most are helpful and work well in the piece, but some of the faster rythyms 'clutter' the piece and make it difficult for easy listening (example: measures 46 and 47). I like the key signature changes throughout the piece- they help move it forward. The ending note is too short... I'd change it to a half note or even a dotted half note (especially at the tempo you've ordained, the quarter note makes the ending sound like it was hit over the head and knocked out while the ending note was being played

).
Was this piece played at the festival, or didn't it work out? Anyway, you did a nice job of working with the three instruments- I find it very difficult to work with brass, but you did it nicely.