I'd imagine NOA has a problem more with the content in this game. Since the game is about a guy killing monsters and feeding their hearts to his girlfriend to prevent her from becoming a monster, that doesn't exactly sound like an easy sell to a North American audience. Actually that wasn't a good sell to the Japanese audience either because Pandora's Tower only sold around 30,000 copies over there which is much worse then Xenoblade and The Last Story which both managed around 150,000.
Of course the mediocre gameplay didn't help the word of mouth in Japan so yeah, that's where the quality doesn't help either. I've watched a lot of gameplay on Youtube on this game and while it doesn't look bad, the action gameplay looks as generic as possible with nothing that really sets the game apart from any other action games out there. The only thing that makes this game somewhat unique are the dating sim elements with your girlfriend that you have to do if you want the best ending which didn't look very interesting to me and I've heard people who've played the game say isn't very good either and makes the game pretty tedious if you want the best ending.