I mean, fire emblem isn't terribly light now days, and it's mega ten, not shin megami tensei.. which includes persona 4, devil children and the last bible series. So it's not entirely off the mark. I watched a lot of the gameplay (a LOT) and it does get awfully creepy/dark at times. It reminds me a lot of persona 4 how the characters are happy and enjoying themselves then every once in awhile things get really strange for a moment. I think the only real problem is the fact they chose the idol theme. If this game changed JUST that main concept to something even bland and generic (stuck in the tv world..) it would have done a lot better.
But that said there are still a few other problems. For example, in shin megami tensei, we have hundreds of demons to play around with. In persona, it's personas but the same thing. In this we get one mirage each. It's like if the main character simply couldn't fuse or change his persona. I could rant about this all day but i've actually got to leave.. i might edit this post a bit later.