Overall good, but still has flaws.
For example, I enjoy the fact that note progressions are randomized, but one must have A LOT of hand-eye coordination to play. Also, something I noticed playing for the Armor Games pick:
The notes aren't in sync with the music. I would up finishing the song like 3 notes after the music had stopped. That's a MAJOR bug in games like this. 8/10, 4/5, good job, still needs work.