I've only heard of the game once before you said it so I had to look it up. I obviously havn't played it yet ^_^ but anything with Flonne and Etna in it has to be a great game. So far I've seen generally positive reviews.
I always loved Nippon Ichi for their Disgaea series so I might give this a shot. For Disgaea fans, I'm surprised Laharl isn't here for more screen time.
I have a question though. Can you level up 9999???