I'm not very good at coherently writing my opinions about games, but I'll list some point here and state my thoughts about them and see what happens, now that I've plugged 160 hours into this game.
First and foremost, the story, even in regards to the Metal Gear Solid universe, isn't great. The location and timing of MGSV has lots of potential, and I felt that they touched upon a lot of it, but were too afraid to fully dip their hand into the meat of it (or it was cut out of the game, either Kojima's or Konami's decision).
I'm glad we got to see Eli, Liquid's arc in the series has always been a favourite of mine, especially due to his MGS1 VA. I am sad that the Lord of the Flies mission was cut out of the game, it had a lot of potential. A teenage Liquid Snake piloting a Metal Gear as you and your entire army try and take him down across a small island. I'm holding out that it'll be DLC, but I know that's a pipe dream.
Skull Face, while dying before he had his chance to shine, was a great villain on face value. I mean, his name is literally Skull Face. His VA was great but his motivations seemed unclear. Was he just pissed because he did all the admin for Snake? Did that reach into his hatred for Zero? What was the point of keeping his XOF team secret (I think this is mentioned in a tape). His homeland and tongue were taken from him, so he, wanted to do the same to everyone else? Including English, which is what he spoke? I didn't really understand WHY he was the way he was, but I know that he was imposing for it.
Quiet, I liked. She was great. The whole "feelings for Snake" thing started to make me cringe near the end, and, her appearance, while I myself am not offended by it, can see how others see it as tacky. The points that Jim Sterling made in his video are pretty much my thoughts here. I didn't like her ending mainly because we can't use her again, but also, again, felt she had a lot more potential.
Microsoft Ocelot is just Wikipedia, pretty ambivalent towards him. Felt like he was a different character here than in any other game, but that's Ocelot. Kaz is an angry prick though that's fair enough, and Huey's a dick.
The Man on Fire seemed to be injected into the story for continuity sake. It's like Kojima said "Hmm, I need a way for players of previous games to feel like their commitment is appreciated, I know, I'll stick a dead Volgin in the game and make him into a man on fire, controlled by Baby Psycho Mantis, because, reasons". Mantis could have been better utilized too, the room for hallucinations and flashbacks in the game were vast.
Imagine running through Afghanistan and coming across a squad of enemies that immediately start firing upon you, and you start firing back. But you realist over the noise of heavy gunfire, that they're not hurting you, nor you hurting them, and they're simply just part of your imagination. Or you could have had the voices of people like The Boss while you're fighting, "Remember the basics of CQC" as you take down four people with your bare hands. Yes it's a bit fan-wanky, but after MGS4, I felt Kojima reigned it in to try and tell a serious story in a universe that has a a family tree of pant-shitters.
I don't really mind the twist. It makes sense, it's not detrimental to the story, it's just boring and pointless in the grand scheme of things, and presents more questions than answers.
Gameplay and control-wise, the game is top-notch. Goes without saying it's the best controlling MGS game, as well as best looking. A shame that we'll never see Fox Engine EVA though.
The missions and landscapes that they take place on were varied enough for me not to be bothered that a lot of them were essentially "kill him/extract him" yada yada yada. I felt, despite being much shorter, Ground Zeroes did better in that department. In GZ, you had to listen to conversations, spot the right man and extract information, then find whatever item/kill whoever. It's side-ops were a massive step-up from those of TPP, I really hate how you spent a lot of time and money upgrading your helicopter when you barely use it. The extracting Hideo mission in GZ was one of my favourites, where were those in TPP? I get that it's an open-world, but that doesn't restrict the developers from creating a few scripted missions. I feel like the open-world nature of The Phantom Pain expand its horizons in the gameplay department, but restricted it in its narrative and coherent one.
There's a lot of things I'm sad about, but tons of things I'm really happy with. This game will take a while for me to have a definitive opinion on it.