Nice work man. I have a novice's grasp of theory, but since since I've been listening to more classical music lately, now I at least know what counterpoint is. And yeah, liked the key changes too. Can you play this as well?
And on a side note, it loops pretty seamlessly well. I just happen to keep my media player on repeat. If it weren't for that very last note of resolution at the end, I wouldn't notice when it repeats.