Good... except I can't believe you used that chord progression. C'mon... seriously? :3

One critique is that the horn sound you used is wayy too high velocity for the feel you want. Use a mezzo forte or mp volume/patch but just bring it up in the mixer. Remember that even within instruments is a range of feels that should be carefully watched.

I really like the B phrase. A lot of people make B phrases that are really bland or not contrasting enough, but you did a good job bringing in a new feel for a bit.

I question why you chose the piano for the A section march. I think a brass ensemble would be able to symbolize the feeling of a march a bit better, or even an emulation of fife-and-drum. Programmatic music is something where you should never be afraid to use something out of line or unexpected. :)

One recommendation is to have a bit more variation in your melodies and ostinatos (repeating patterns). Perhaps have the snare pattern change every 4th measure or likewise with other instruments, having certain times slightly different. This keeps the music fresh and evolving even through a buildup.

I also think you could use more orchestra in this... I understand the need for an intimate feel, but soldiers marching? I'm thinking full steam ahead orchestration-wise. Also don't be afraid of ornamentation, either within parts or just by adding counter-melodies to the piece by adding other parts (a few nice woodwind ornaments never hurt anything).

Keep compos(ed/ing)!
-Samulis