Thinking more on it, I wonder if he's aiming to create a new IP or make this a self contained story. I know pretty much every MGS after 2 was "his last" because he wanted to move on to other properties and ideas. I'm confident it'll be great regardless, but I hope he doesn't get himself trapped in another cycle of sequels to appease the masses while constraining his imagination. Then again, from what we've seen, I don't know what else you could add to this that'd be out of place.
I agree with the above notion that it feels almost like it has an RE tone, though I'd side more on Silent Hills. Those inky silhouettes give an unsettling feeling, much like many of Silent Hill's human-esque enemies. I imagine the larger creatures that they're tied to will spike that feeling. I'm interested in seeing who you're fighting against. This is the first time we've seen Sam fight human enemies. They seem to be trying to catch him as well what with the electric prods and such. I had a moment of "fuck yes" glee when he picked up a package that got knocked off him and started bludgeoning the guy with it lol.