I was kind of disapointed with Ni No Kuni. I didn't hate it, but after the great story buildup in the first half of the game, it really didn't deliver that much in the second. Overall, I still enjoyed it, but at the end of the day the story had me going "meh" a little.
Also, I really didn't care for the Familiar system and the AI was pretty bad. If there ever is a sequel, this was still a pretty good foundation.