I think etherealwinds is on to something here. I downloaded your piece out of curiosity and analyzed the phase and just to mess around with the frequencies. The beginning does sound like it's in mono but it really just gives that illusion because the combination of too much mids and most everything is panned to the left. The instrument you have on the right isn't very present and so it's just out of balanced, and I would have the bass more centered. The piece sounds much better mix wise when I make the low frequencies more present via the EQ. What microphone are you using? The piece sounds much more full at 2:23 and beyond. But I do like the mallets.
That being said, the composition and your lyrics are gorgeous. When I get passed the mixing issues, I really don't get tired of this. Your singing is great, and I like the progression you have going. The different parts that you have the instruments play in the last quarter of this piece is great to listen to.
Besides the mixing sounding a bit narrow, you have a lot of good ideas. I like the drive this piece has—very uplifting in a sense. I have to admit that despite its flaws, this is quite alluring, and I can't quite put my finger on why. Perhaps it's the combination of your lyrics, singing, and progressions that really makes this piece. I hope this was constructive for you. Mixing will come in time, and I have to admit that after composing something we are left with little time to mix within the 2 week span. I hear a lot of mixing issues in my piece as well so don't get discouraged.