For music made with Beepbox, it's pretty good.
There are some nice-sounding melodic passages in particular, which reminded me of Zelda a link to the past (SNES).
On the other hand, it's very difficult to hear the tempo and rhythm correctly. It would be easier if the percussion marked time. Your percussion marks a lot outside of time, and even outside of off-beats. That’s a bit confusing.
Otherwise, the use of few instruments and the two brass instruments in the melody convey the martial aspect well.