Great job!
Dude, your compositional skills are outstanding, and this piece shows that for sure. My one bit of constructive criticism would be that you should master the voice a little better next time so it sounds a bit clearer, but that is assuming that you didn't intend for the voice to sound the way it does. I mean, to be perfectly honest, besides the ever so slight voice difficulty, this piece is practically perfect. I would just work on mastering it a little better next time so it doesn't sound too crowded at certain points. If you don't yet have a mastering program, i would suggest izotope ozone. But anyways, you have done a fantastic job on this piece. It would fit perfectly in a castlevania game.
Now, honestly, i'm really curious about what sort of approach you take when your writing your songs. Meaning, do you start out with the beginning and just improvise from there, or do you lay out some sort of plan and then follow suit. Because, whatever it is that you're doing, it's working 100%.