I realize I'm late to the party on this one but I nonetheless want to talk/rant about how I found FFXV to be lacking in multiple ways. This is just my opinion and I have no issue if you love this game.
First off, the world is not fleshed out nearly enough. While we do get a nice bit of info about our heroes' homeland of insomnia, Niflheim gets practically nothing other than they dress up like knights and are evil cuz evil. Compare this to The Nilfgaardian Empire in the witcher series, specifically witcher 3.
The northern kingdoms occupied under Nilfgaard may lack the rights they once held under their own governments and punishments for even small crimes are much, much harsher than previously. On top of that the empire sees fit to repress northern culture, seeing it as barbaric and uncivilized in a much similar fashion to the Roman Empire.
Despite all that not-so-good-stuff Nilfgaard is not entirely or inherently evil as while their laws maybe overly strict the result has greatly lowered crime, least in certain areas within the occupied north. The economy is also a lot better as the Empire pours its resources into the lands of the nordlings. The war between Redania and Nilfgaard spreads jobs as blacksmiths need to make blades, farmers make more food, and the two forces need more soldiers.
But as powerful as the Empire is, the war has spread Nilfgaard to the nation's limits, civil unrest rises back home as both the peasants and nobility must pay ridiculous amounts in taxes to pay for a war that most of them seemingly don't care about.
Niflheim by contrast is an evil empire with next to no good qualities and have a more or less infimate amount of resources, soldiers, and power to crush any resistance.
Other than some loading screens that say the emperor used to be nice, we don't get much on them.
My other point is the combat, it's like square doesn't know if it wants to make a Kingdom Hearts style hack and slash or use the active time battle system. So they do both... kinda. Square seems to be convinced that no one likes traditional turn-based JRPGs anymore, dosen't help that many game journalism sites consistently decry turn based combat as being "old and outdated".
My question to that is how is third-person action anymore new? Both forms of combat have been in gaming practically since gaming's beginning.
And finally, the main cast isn't interesting. Other than Ignis "I've come up with a new recipe" Scientia, the crew is rather bland.
Noctis is a generic teenager, Gladio is nice eye candy but not much else, and Prompto is Tidus if you took out all the personality and made him sing about chocobos every five minutes.
As I said I have nothing against you (dear reader) if you enjoy the game, I simply didn't care for it.
Edit: More things to complain about.
I never bothered to finish this game, I got as far as the last chapter but found out that I just didn't care about anything going on. I won't spoil the game, but even Gladio's rippling muscles couldn't save how bland everything was.
If not for the fact this was a Final Fantasy game, I would have never made if through the first chapter, let alone most of the game. My love for previous titles in the series kept me slogging through the endless amounts of boring 'kill this number of monsters' quests.
Meanwhile, the characters that are actually interesting (Ravus, Aranea, Camelia) are tossed to the side, unless you buy the DLC.