Let's call it what it is. A super cutesy simple rhythm game with great music, a nice difficulty curve, and.... uh... well, thank God for the "the characters are now all cats" option.
Seriously, the in-game character models are chibi goofiness for the most part. Their models in the menus and in loading screen art, however, make this a game I can't play around children.
A more modest option would make this game pretty much perfect. Stop making the "don't ask how old the girls are" joke.