They weren't kidding when they named it "Darkness"
I don't think this is a good game for little kids, but it's great play if you don't get scared easily, love good plots, and are a decent gamer. That being said, this story is complex and more violent then GameFreak (or Nintendo) has done to Pokemon before, I don't understand why the game ranking people gave Pokemon Rumble E10 but this (and the older mystery dungeon games and also ones yet come, most likely) snuck though with an E, you have to save a baby kidnapped by an implied pedophile (it's not an optional sidequest, it's actually quite plot-relevent), here some of the enemies want to kill you and your partner, there's an insane god, you're actually an amnesiac terrorist, and you fade into nothingness as the partner watches. But the partner, Wigglytuff, and the rest of guild are all great role models, the partner is so kind and sweet that it's actually an important plot point, and forgiveness is something that there's a large emphasis on. But this is still really scary at times. You might want to read a summary of the plot first, just to get a good picture of the game, though.
This title contains:
Positive role models
Violence & scariness