Hi,
I just joined YC. Please let the newbie comment :)
Interesting approach! Vocaloid2 has definitely become quite good, and I was always interested in playing around with it (but never got around to it). So it was interesting to see someone using it.
I like the complex yet beautiful chord progression, and the style of accompaniment works well with the character of the piano. However, while I agree that the diverse harmony progression keeps things interesting, as a song for vocal + piano, it also made it a bit "hard to follow". The structure of one theme is so complex that I lost track and didn't quite remember the beginning of it. So it happened to me that I didn't realize when the song entered the second verse ;). After listening to it about 3 times I can see the structure better, but it did take a couple of playbacks to understand. (Maybe just me).
I guess the reason why vocal dominated songs are kept simple is because the main feature should be the voice and the words. Adding complex chord progressions can be overkill (even if it's nice sounding), and that's what I felt a bit while listening to it. Maybe it works better as a purely instrumental piece?
Anyways, it's beautiful nontheless, and I enjoyed it a lot! And thanks for mentioning the lyrics are random words. I was about to start deciphering haha!