Positives
The thing that really got my attention when I first saw the game was the style. While there are a handful of games that share a similar look, none of them do such an incredible job as Ni No Kuni does. The visuals, along with the music in the game literally make you feel like you're playing a Studio Ghibli film. The soundtrack was written by Joe Hisaishi the man responsible for the soundtracks to most of the mainstream Ghibli films and the quality is fantastic. So in terms of looks and sounds, the game is extremely pleasing.Even the plot itself is pretty standard Ghibli film, although Ni No Kuni get's pretty ridiculous at times. But overall the world that has been crafted is phenomenal. It's clear time has been taken to give the other world a lot of character and story. Just by looking at your magicians handbook this is apparent by the pages and pages of stories and detailed descriptions of all the familiars among other things. I found the plot to be quite refreshing because while the ending itself was fairly predictable, the route between was unexpected and fun.
Negatives
While I'd love to end it on that positive note, I have to discuss the game mechanics. There isn't a whole lot about the game mechanics that I can say is original, if anything. Ni No Kuni plays just like a generic JRPG, with the overworld exploring, enemies randomly populated and avoidable, down to the way it handles quests. Speaking of quests, there are a ton to complete but unfortunately they end up being extremely stale very quickly as they almost always devolve into the same basic types of quests.There is a type of quest that involve restoring lost pieces of heart. This concept plays a fairly large role in the story overall, but the side-quests end up being almost pointless. I swear, you end up repairing the broken hearts of nearly every NPC in the game by the end. While I like the concept, I didn't like that literally half the time the person with the piece that you needed ended up being a few feet (at least on the same map) from the brokenhearted person. The fact that they are usually really close to each other makes the process more tedious than interesting. It probably would have been better if you could store multiple pieces of the same type and had the people with extra heart pieces spread out all throughout the land so you had to explore to find them all.
The other majority of quests involved defeating certain familiars and what not. There were a handful of unique quests, but it definitely felt like a chore by the end of the game to complete them all.
There's several things about the battle system that that really irk me as well. A lot of your battling can be done with familiars, or you can control the character themselves as they usually have some magic/abilities as well. There are a lot of things that are just done for you and it really bothers me. I don't understand why when I switch to another character and they have a familiar out, it instantly recalls that familiar. Just let me do it myself if I want to, what if I want that familiar out, now I need to throw it back out after it getting forced recalled.
Other things that were annoying about the battle interface include: Whenever a skill or spell get's cast with a quick cut-scene whatever selection I had selected in the action wheel would get reset to the start position (attack). You can assign roles for your currently uncontrolled player, but these roles reset after every battle. Any in battle cut-scenes from skills usually cancelled whatever action I was in the middle of performing, even when from teammates (such as, trying to cast a fireball, but teammate does another skill, come back from cut-scene and now I'm not casting fireball)!
I really despise the action wheel overall. I think the battle system would have been better off if they just assigned different actions to the 4 buttons like, Defend, Attack, Skills (whether it be magic, or tricks), and provisions. That way any action would be readily available as opposed to having to scroll through your actions with "trigger" buttons on the controller.
The overall interactions with people and objects was sometimes frustrating as well. I hate it when the game doesn't let you perform certain actions because it "isn't time yet". There was many a time I came across something and knew exactly what spell I should cast to read/open/do whatever on an object and it simply wouldn't let me or do anything because I "hadn't got to the right point". In certain circumstances I can understand this but it get's frustrating when every monument you come to you simply can't read because you're not doing that quest yet. And there's no cipher or anything that you're using to decode it, you just can't read it for whatever reason. I really disliked how the game would hold your hand as well. Many times an action could only be performed when the game "let" you do it. So you'd have to talk to someone and that would open your spell menu, as opposed to just letting me open my spell menu and choose what I should do.
A few other things: It bugs me that the game gives you spells that you can't actually use. That and the fact that a handful of spells that you are given are only used in maybe 2-3 cases. I don't like that there's really no challenge in knowing where to go next, even after turning off the guiding star the solution was usually really obvious.
Oh and, one word, Casino.
Familiars
The whole familiar and battle system is something akin to a real-time Pokemon battle. And with the sheer number of familiars that are in the game (400 I believe), that's not an unfair comparison. There is a ton of systems that go into the familiars and I feel like it's incredibly easy to not know what the hell you're doing. I'm pretty sure I have the worst familiar team lineup you possibly could. Playing on normal I found certain parts of the game to be incredibly hard, even after grinding a good amount and I fear this is because my team is horribly mismatched. This is a problem.It'd be nice if the game gave you some indication as to how balanced your team and/or what you're missing or if you're under-leveled in an area. I would find that even in areas that I've cleared I would sometimes inexplicably lose to a random group of familiars that I'd beaten dozens of times before. Ironically I never had problems with bosses as they were predictable and block-able. But when you have multiple enemies and their battle interface isn't very friendly nor did it have quick response to input, it makes management a nightmare.
Honestly, I don't think they really needed to have 400 familiars in the game. You only end up with a handful of them and they kind of end up in the background anyways and are not an integral part of the story other than being used for battle.