The gameplay part of MGS5 is really good. The pre-engagement scouting and infiltrating, the various methods you can utilize, the wonderful control interface, ya buddies, running to the helicopter blasting "Maneater". All at 60fps with super-clean image quality. That's all dope as fuck.
But everything around it is kinda...not great? It's a bit of a failure of an open world.
Like I mentioned before, traversal just sucks ass. Getting from one place to the other is a chore. There are closed off, blocked off paths everywhere. Its not particularly visually interesting, no memorable monuments to guide your eye, or NPCs or anything.
People complain with "what do you want, another UbiSoft collectathon", and I mean...the whole fuckin' game is a collectathon anyway lol. You collect black carrots and golden flowers, and minerals and resources, and soldiers and animals, and blueprints and weapons, and hostages and intel and its all part of this weird ass micromanage minigame. You go back to base, take a shower, realize that's jack all to do here besides smack your soldiers around and some boring target ranges, then fly back to the non-sandbox sandbox.
Maybe if there was any kind of narrative momentum, that could help in spades. All the other open worlds always have a "main path" you can get back to when you feel like progressing the game, but half of the missions in PP you do feel like filler. Which doesnt speak well to the Side-Ops which are like, ACTUAL filler, going back to the same outposts and camps the main missions already covered(or vice versa).
IDK its like...its like they didn't really understand the whole "open world game" thing? And they tried to marry various MGS concepts to an genre they clearly aren't familiar with and it doesn't all work?
None of this shit really matters when you're at the cool locations and experimenting/infiltrating/shooting/sneaking/blasting music, but there's a LOT of time spent in this game doing stuff that's not exactly great. That doesn't really feel like MGS, but some weird Splinter Cell/MGS/Monster Hunter...hybrid...thing.