Finished FF16 an hour ago and my overall impression of it is that it's bad, not absolutely terrible but worse than being simply mediocre. Just about every part of it is not well thought out and in a lot of ways detrimental, the only good thing is the graphics but I'm sick of particle effects spam, not to mention the fact that they are used so much that the later fights I got hit a lot of times by not being able to fucking see what the opponent was doing.
I'll start with the gameplay. It's fucking terrible and inexcusable in a game post the Playstation 2. Barely anything changes from the beginning to the end. No new weapons or strategies, few of the Eikon powers you get have gameplay reasons and pretty much none of them are worth using past the first one as the game is built to not require them, or have them actively be more dangerous to just playing normally (for example Odin's ability requires you sperg out on enemies, which is extremely dangerous and not viable on bosses). Combat fights are the same and never really change, the only change once in a while is enemies readying a one hit kill ability so you just hit them with all your abilities rather than wait until they are staggered. Your only ally in the game is a wolf that is basically useless, and to add insult on injury isn't even fucking usable in the final boss. There isn't even any elemental affinity part, which you'd think would be important in a game centred around getting new elemental abilities.
There is also no exploration or customization. All the accessories in the game are shit (of the maddening variant of +3% increase in power rather than something that changes your gameplay) and all the equipment is just a flat stat upgrade. There isn't a single chest worth opening and only few quest rewards are worth the bother. Any quest reward will also be quickly upstaged by equipment that you can buy in the shop, literally you get the legendary sword of your forfathers in one mission only to immediately buy a better sword once the mission is over. There are also no spells to buff yourself, besides using some move names there is generally no connection between this game and final fantasy.
The Eikon fights barely ever happen and are more glorified cutscenes than actual gameplay, the game never lets you transform without some reason in the plot. Why not have some big monster battle with it to spice the gameplay? The game even has shit quick time events which aren't even hard because there are literally only two button variations of them, and probably you can't fail at most of them.
The plot is arse. It starts by making itself appear like it will be more adult GoT style deal but it never fucking happens because THE WHOLE POINT OF GoT IS THE INSIGNIFICANCE OF INDIVIDUALS (at least before it went bad). Like if it was a Tactics game it might have worked due to having a ton of disposable characters, but not in a game where the entire point is the one guy saving the world with his dog. The whole world politics barely affects the game besides giving it the illusion of depth, you never have any choice and the world gets shittier by the protagonist's actions yet he is constantly reminded how he is a good boy so he shouldn't take it to heart. It also has some weird tone changes like suddenly having an uncle character which should have a laugh track with his cringy actions. The game's world has uninteresting lore and suffers from being so childish in world building that you don't really care about whatever history it has. It all amounts to "people using magic dindu nuffin" despite the fact that settings like 40K have made such premise more nuanced.
A good example of how bad the writing is that in one point the protagonist is having issue with accpeting the fact he killed his brother, despite showing the viewers beforehand that the brother still lives, completely undermining the revelation and conflict, like who wrote it? The game even does the Kingdom Hearts bullshit of having multiple characters wear the same article of clothing covering their faces for conflict sake despite the fact that it's a retarded coincidence.
The final villain is boring and uninspired and might be the worst villain in mainline FF games and the ending is underwhelming and cliche as hell (and feels like a retread of 15). Also has one of the worst lines in the last fight - "The only fantasy here is yours. And we shall be its final witness", fucking cringed in my seat.
If you want a semi decent FF action game play Stranger of Paradise which actually has connection to the series in gameplay, very based and a much more impactful ending.