Normally I wouldn't have bothered to review this, as its something out of my comfort zone, but I had to stop and give a major applause on the mastering to this song. I really can't think of any way you could have hit the mastering any better. Every sound is perfectly crisp yet smooth, and flows evenly with next, it's all equalized very well, it's just very well put together.
As for the melody itself, it stays fresh throughout, staying pretty much the same while managing to mix things up at regular intervals. I particularly liked the chiptune-esque sound around the 3 minute mark. Beyond that I'm not particularly suited to review this more thoroughly, since like I said, this isn't the sort of music I typically listen to.
Overall, very good, 9/10.