I don't agree with the gameplay mechanics being substandard. Can you define that? Because I haven't played a FPS this generation that made me feel better playing than this one, gameplay wise, maybe it's just me, but the 60 fps help to enhance the experience even more.
The usage of weapons felt clunky to me as the movement. F.E.A.R., an "old school" shooter, had a real natural weapon feel for its age which I would expect this game should have at least reached. The sequences where battles had a Matrix like feeling when you could destroy parts of the environment had a visceral feeling Wolfenstein felt stale in comparison.
But my main issue was how most of the battles played out in reality. For instance when you're using the energy weapons to deal with enemies the low ammo forced me to permanently backtrack to the energy station for a reload. There was no real flow to battles that way. Maybe it was my game style but then this game forced this on me and not vice versa.
The "stealth" elements of the game were an utter disgrace and felt more like a parody. I had just played Splinter Cell Blacklist before and this game was just smooth and slick in whatever you did. The game mechanics gap was staggering.
Then there were the technical issue with the weapon wheel which caused a lot bogus selections because it was so cluttered. Each wrong selection needed a reset of the primary/secondary. They could have minimized that problem by not putting the dual setups there at all but only allowed this by d-pad. This really annoyed me as it was so unnecessary.
A few game situations were broken/weird. When you landed back on earth and had to fight through the room and died you lost all your weapons/ammo and the weapon pack at the landing zone too. So you had to fight through this with close to nothing. I think the game also lost some item there I couldn't recover anymore for completeness. IMHO a bug.
The final boss fight underground also felt "unpolished" because it seems to only be survivable if you forced the boss into an environment position the "AI" didn't allow him to walk from anymore.
So my conclusion of the game is that the narration/level design was really entertaining. It was also long which most campaigns these days unfortunately aren't. But the technical implementation were a disappointment to me.