It's an All-Age game 
But consider it has been develop for the international audients, I thinks it have some significant in their own   
Still what I not quite happy is that they reuse some of other Overdrive's Games BGM 
the music does fit the mood of the game but still It gave a feeling of budget game   
I will said if you really like to know & travel to Japan this game is a great introduction, so give it a try!