The start is too slow.
You don't even hear the main melody until 1:26, and I wouldn't be surprised if a number of people rated it down and left before getting to the good part.
The song itself is really good. I liked (and downloaded) the original ReonakRhythm version, and I like the A->N version even better. I've been waiting for a while now for you to release it (or a variant like this) on Newgrounds.