It's getting good reviews. 85 on metacritic (55 reviews).
http://www.metacritic.com/game/playstation-4/ni-no-kuni-ii-revenant-kingdom
A few snippets, with a range of scores:
Easy Allies, 95:
Some may argue Revenant Kingdom clocks in a bit on the short side at around 30 hours to finish the story, but it’s a nice departure from the trend of top-rated JRPGs that last 60 hours or beyond. Ni no Kuni II is a brilliant follow-up that outdoes and improves upon its predecessor in just about every category. This is one fairy tale that most certainly earns its happily ever after.
Attack of the Fanboy, 90:
A great cast of characters and a wonderful story, it's tough not to fall in love with Ni No Kuni 2. If you're looking for a world to get lost in this is a game that will provide you with many hours of enjoyment, amazing you at every turn with a barrage of beautiful imagery, incredible music, and gameplay to match.
EGM, 85:
Ni No Kuni II is full of some tremendously creative decisions that make this unlike many other Japanese RPGs, as well as a clear step above an already good game in the original Ni No Kuni. However, some additions like the RTS elements left me scratching my head. Despite this, Ni No Kuni II tells a beautiful story that’s set in an even more beautiful world, and should be enjoyed by most JRPG fans.
Game Critics, 85:
Ni No Kuni II is absolutely delightful. While the original was bogged down by some cumbersome mechanics, Level 5 has done an outstanding job of cutting the fat while adding new elements and keeping things fresh — It has almost none of the filler that plagues the JRPG genre. I can’t stress how happy it makes me to see a game as good as this appeal to both someone like me, and to children as well. But most importantly, it’s not a kids’ game — it’s just a fantastic JRPG.
Push Square, 80:
Between being a relatively traditional Japanese RPG, a kingdom management sim, and an advocate of real-time strategy, Ni no Kuni II: Revenant Kingdom could have easily stretched itself too thin, but developer Level-5 somehow manages to pull everything together and make it all seem worthwhile. This is a robust but accessible adventure that's stuffed with charm and character. A really fun combat system and gorgeous visuals top things off, making the sequel a joy to play. In a word, Ni no Kuni II is delightful.
Game Informer, 80:
Building your kingdom is satisfying and engaging, even with the weak narrative hooks. The cycle of rewards became an obsession, and had me staying up late to recruit just one more ally, or complete just one more upgrade. Combat could be tighter, and other supporting elements could use some polish – but like any kingdom, this experience isn’t about individual contributions. It’s about how those contributions come together, and the fun of this experience as a whole outweighs its flaws.
Gamespot, 80:
It's chock full of excellent battles and surprising moments that make for a far more memorable experience than you initially expect and leaves you impressed by your own accomplishments. If you didn't play the first game, don't let this one pass you by too.
IGN, 78:
Ni No Kuni 2: Revenant Kingdom distinguishes itself from its predecessor by layering fast-paced, real-time combat and an engaging kingdom building system atop more traditional RPG systems and quests. It’s a shame it delivers so few truly memorable characters and restricts so much of its storytelling to text on screen, but by the end of Ni No Kuni 2 the broader themes certainly resonate and the 40+ hour journey has been well worth it.