1. HP restore in dungeon is more convenient than staying at an inn
Every dungeon has a save point/HP-MP refill right at the beginning and all these dungeons can be teleported to just like a town. Inns require more walking, talking, and cost money. Just put the same refill save point at town entrances and be done with it.
2. Names of areas not shown while flying
Just fly to Swan Island. Where the fuck is that? Sorry, no matter how many times you've been somewhere I can't let you know what it's called unless you land first. Hope you like hearing that trumpet sound for summoning your flying dragon...
3. Can't turn off specific spells
And as a result the AI will spam spells at random blowing out its MP in about 3 enemy encounters.
4. Shit options for AI battle tactics
My AI options consist of Do whatever you like/Go all out!/Keep allies healthy/Don't use MP/Do nothing at all. The first 3 options all seem to act the same way and involve your allies spamming spells without regard to MP cost and nervously healing allies as soon as their HP falls to 90%. The fourth and 5th options might as well be called "Let yourself die." What about "Use MP sparingly" or "Heal allies when in danger" or "Use buffs/debuffs"? Dragon Quest has had such AI options for at least 20 years now. There's just no excuse for AI options like Ni no Kuni's this far into the life of the RPG genre.
5. Poor indicators of enemy difficulty
It's pretty common to get wiped out by a group of regular enemies walking around the overworld map. Thinking about seeing what's on the other side of that bridge? Ha-ha you should've known that cute little group of fairies would annihilate your entire team with just physical attacks (seriously, this happened to me). The only sign the game gives about the enemies' strength relative to your own is that, if your level is high enough, they will try to avoid starting a battle encounter. Even then, there were a few times I ended up having to run for my life even though my group was supposedly superior. Plus, unlike most other RPGs every enemy just looks so cute that it's difficult to know what you've gotten yourself into until the battle has already started and Oliver is standing there with two dead friends after the first round wondering what the fuck just happened.
6. Not enough MP to justify use for most of the game
Especially early and mid game where one healing spell costs 11 MP out of your healer's total pool of 60. Let's say your whole group gets zapped by an enemy spell and loses 1/3 their HP. Your healer then goes about trying to heal everybody individually and uses up half their total MP in the process. A lot of enemy attack skills are also way over priced when you realize it costs over half your MP to use a skill that will do 120 damage but simply running up to the enemy and quickly whacking it 3 times would do about 90 damage.
7. Low accuracy for debuff spells but high MP cost
Similar to #6, most debuff spells are also expensive but have terrible accuracy. Battles are usually so chaotic that it's difficult to tell if it missed because of bad luck or because the enemy was immune. One quickly notices that it's more efficient to just use physical attacks and save the MP for healing.
8. Enemies can use spells without regard to MP cost
Mostly it seems enemies are just programmed to let loose with a high damage special attack early in the battle and then again after a certain number of turns have passed. This goes double if there is more than one of the same enemy in the group so you'll often get hit with something nasty like Lullaby followed almost immediately by another Lullaby.
9. Brokenhearted side quests are dumb
90% of the brokenhearted quests involve talking to an NPC and then immediately talking to a different NPC a few steps away in the same area of town. I guess I should be relieved I don't have to trek all over the world to complete these quests, but why are there so many of them?
10. Can't target certain enemies until others are dead
I don't know if it's a hidden enemy trait or what but several of the Bounty Hunt monsters had minions who, despite your best efforts to target them, simply cannot be attacked (without resorting to expensive AoE skills) until the enemy leader is defeated. This I found especially difficult to accept because it felt like the normal rules of the game had arbitrarily been changed.
11. Can't change targets once selected
Another frustrating one. Once you tell your monster to attack an enemy, they cannot be made to attack a different enemy even if you cancel the attack and wait for their attack turn to come up again. You simply won't be allowed to target any other enemy until the first one is dead. The only way around this is to recall your monster completely and choose it again, which wastes valuable time.
12. So much text for a simple find X item or kill X monster quest
Trying to flesh out your game world through dialogue is fair enough but this game has about 150 errands to do and almost all of them involve NPCs who have zero impact on the main story. Yet each one seems determined to make sure you know the sad chain of events and motivations that have led them to asking you to go fetch 10 bowls of rice and 3 super curry spices for them. I quickly learned to just hammer the X button and look for the red text that told me exactly where to go and what to do.
13. Skills that cancel actions and make you have to pick again
Certain skills in the game come with a brief animation that inexplicably cancels all other skills that are waiting to be executed. It's not that you have to watch the animation, it's that you have to actually re-do the input for it. Most games use a que system that remembers the action you wanted and executes it when it's ready. Ni no Kuni says fuck that reasonable shit. The first person who get's their spell off also gets to make every member of the opposing team forget what they were doing because BATTLE TACTICS!
14. Uninteresting post game content
The new game + is usually where RPGs let players get into some high level gear and strategy for challenging enemies. Ni no Kuni just offered more of the same. Gold versions of monsters, more errands, an S-rank colosseum battle, more casino gambling. There may have been a bonus dungeon (I doubt it) and It's pretty rare that I walk away from a new game + since they're usually my favorite part of RPGs, but as soon as I saw more errands to do I could not bring myself to pick up the controller again.