This song really doesn't feel like it goes anywhere. The build up is miles long, and then it's still really naked. Percussion is really rudimentary.
The tempo change and key change are fine, but this piece lacks almost all of the gravity you wanted to convey not only because of the emptiness, but because the percussion instruments you chose don't lend to it. This sounds like a song someone would perform in beginner band. Also, where are cymbals? What are transitions and structure? You should really ask yourself this. Also, one of your progressions is a scale toward the end. We start and end in the same key, so this isn't a biggie, but I was mostly just bored.