Good concept--a few suggestions to make it more enjoyable:
-The lag in the eraser movement seems unnecessary and feels a little sluggish, so I would remove that or make it bit less.
-Dying after one missed note seems a bit unfair--I'd give 3 lives or something.
-Agree with the other comments about rhythm game: if you can find a way to sync the falling notes with the beat, that would make more sense
-Add some sound /visual effects for when you capture / erase a note successfully