Fair warning, I'm shit terrible at rhythm games and haven't played a whole lot besides the standard DDR assortment and Parrapa/Lammy.
The game so far seems to simplistic right now, since it's only got the one constantly coming wave line and nothing much else. The Idol on the side is cute and all, but there's no reason to look over there while playing. Other games like Parappa have interludes that let you pay attention to what's going on and some development on whatever situation got you into calming a bunch of babies, and are non-distracting enough during regular gameplay that you can focus attention on the sick rhymes and not the cinematics.
Unless the game gets saved by an amazing OST, in it's current state it's not anything special. I hope this gets a little more to it in the future.