I think the other trademark is Kojima, when he's not being weirdly horny, is just "supernatural and weird". Like the other stuff with the floating boy/psycho mantis, man on fire, parasite unit. When you've got the weirdly horny and supernatural mashed together, it's either a Kojima game or some variant of Biohazard (Resident Evil).
My overriding thought would be, ridiculously convoluted story, which maybe-sorta kinda works by some insane internal logic. More like the author thought X would be cool, with no thought of downstream ramifications to a coherent plot.
If you have never seen this summary of the Metal Gear series, buckle up: https://m.youtube.com/watch?v=aaLiLRVeaZA