I think I've spotted which is the main The Phantom Pain's problem:
There's a lack of personality here. Let me explain, and for comparison sake, I'm going to use both Ground Zeroes and Peace Walker, which I don't consider they have a personality problem.
Most of the content thrown at the player is a redone version of something previously, whether it is extract tanks, dispose of a combat unit and so on. Even story missions, most of them, are a consequence of this. My most hated main mission, "Back down" or something like that have you extracting tanks, like the side ops things, but with the gimmick of a time constrain added to it. That's it, there's not much more to it.
So like the 65% of the things you can do in this game are something you've already done, with a gimmick, or just plain the same thing. Fortunately, in my opinion, the gameplay is so solid I didn't mind it in most cases, but I was just talking to a friend here who share the common opinion. This game would have been much more amazing had it had a little bit more of personality.
Let me explain in detail, now. Ground Zeroes gave you one single story mission, then about five side ops to do. Out of those, there were two fairly straightforward missions: the main mission - which is rescuing two prisoners - and the eliminating the snipers one - which was killing two soldiers -. Then they started getting creative, one has you storming through an helicopter the base itself trying to rescue Kojima, the later gets injured and you have to carry on the battle on ground while protecting his unconcious body until the helicopter has enough ground to land. On The Phantom Pain, rescuing Kojima is exactly the same mission as rescuing Kaz, except that, worse yet, there's nothing afterwards. You just grab him, put him on the helicopter and done.
What about blowing up the anti-air placements? There's a twist, once you've damaged them enough, then a timer will start until you finish your objectives because the base you're standing on will get blown to pieces. That's something you couldn't predict from the start.
The worst offender, I think, is that I've just unlocked Raiden to use on the game. Here, in Phantom Pain, Raiden is merely a costume for Snake. That's it. In Ground Zeroes, Raiden had a whole mission dedicated to him, which was also a tribute to another Kojima game and tons of easter eggs to find (like erasing the Metal Gear games logos!), plus fighting some alien shit, even if they were just a re-skin of normal soldiers. See where I'm getting at? Not only that, but you could unlock different colours for Raiden armor as you progressed, but in TPP you're stuck with the normal clothes. What about Deja Vu mission? A whole tribute to the original Metal Gear Solid, which also gave you a PSX textured Solid Snake and Gray Fox? Same thing in TPP, Gray Fox is merely a costume, and Solid Snake can only be unlocked if you played GZ.
Then there's like 16 missions of defeating tank units; the only thing they are all different is that they all take place in different places. That's it. How awesome would have been doing like mission 6 of it, only to find that, I dunno, it's actually a decoy group to capture Snake, and you have to fight your way out of a ridiculously numbered army waiting for you? Maybe I'm overthinking this, but that's the serious problem with the game: things have zero personality whatsoever. Never thought I'd say this, but outside the cutscene "heavy" story moments in TPP, Ground Zeroes had probably more personality poured in it. I bet being semi-open world helped much more too, so I wonder if the trade of complete open-world in TPP was worth it.
Now let me point at Peace Walker. Peace Walker is for me, a boring game, because of the game design (it's much better played on a portable IMO. Tried the game on console thanks to the HD version and...no, just no. Had to force myself through it, and it wasn't enjoyable). And yes, the game has tons of filler. But do you know what it also has? Some of the most creative side missions I've played in a game like this. Seducing Kaz, Monster Hunter mecha hunts and some others come to my mind. Was it so hard to replicate some of those in TPP? Or just use the same philosophy on it?
And to my final point: Dispatch Ops. Completely wasted. In Peace Walker, you had to create your own combat units, choose how many soldiers per units, which vehicles, weapons, tanks and Metal Gears were going into whatever mission you wanted. In TPP, you can only choose...ten soldiers, and everything else gets automatically assigned, and not only that, but there's just one Dispatch Ops worth mentioning, and you have zero control over it. And its difficult is merely an artificial barrier. There's no reason why you have 50% of possibilities to win. Also, did Battle Gear do something? Using Metal Gear in Peace Walker had the risk that enemy could blew it up, but it definitively helped winning so many battles. Battle Gear was here merely for Huey to have some deja vu moment, as Big Boss points out. Another thing wasted, another lack of personality.
There, I think I've covered it well.
