Good Puzzle.

I liked the puzzle, seems like something i could play for a long time. The only thing i think could use some improvement are the graphics, a more "cartoony" look might be nicer?

I like the controls and the concept, it works very well.

I didn't play all the way through it but some more varied goals or methods to reach those goals with be interesting.

There's more to do still :)

It's better than the last time; but there are still some major things you could improve for the game to be really enjoyable:

1. Animations: It looks much better if the notes "explode" or something along those lines when you hit it. If you can do this, it would be a huge improvement.

2. Songs: You need more than one song. Consider using "Creative Commons" Licensed music, (from the newgrounds audio portal for example), because using copyrighted commercial songs might get you in a bit of trouble later.

3. Rythm: This kind of games are mostly made to fit the music. The various notes should be pressed at set times according to the music.
The game feels much more natural to play if you can HEAR when you're supposed to press a key.

4: Backgrounds: This one is fairly simple. Just add something in the background to fill the current black void. Doesn't have to be very fancy, just a picture of something.

These goals might be unreachable for you at the moment, but it's something you can work towards ;)