Thanks for the recommendations, and keep them coming
Probably one of the most interesting and unique games I've played this gen is a little sleeper called Echo. It's stealth, and I'm not sure how you feel about that, but the mechanics are a good deal more individual than the genre usually aims for.
Basically the protagonist is trying to navigate her way through this strange sci-fi palace that seems to have scanned and created copies of her. As you make your way through an area, the palace takes note of what movements and actions you take -- running, ducking, jumping over things, opening doors, walking through water, shooting -- and begins to apply those actions to its copies. Essentially whatever you do, the copies learn to do as well, which means you can make things easier or harder on yourself depending on what actions you decide to utilize.
It's very odd and challenging, and as you can see the aesthetics are generally very unique and surreal as well. It's not horror necessarily, but there is a very unnerving quality to the whole thing.
I haven't finished it quite yet, but it still stands out to me as one of the best of the "unknown and underappreciated" this gen. It's definitely available on Steam and PS4 (I bought it for both). Not sure about the Xbox.
https://www.youtube.com/watch?v=zG5Lh7Uu-EA