In terms of movement mechanics at least. Sam plays somewhat uniquely, in that he moves more like a human being than a video game character. He can't instantly change directions, he can't immediately cancel his momentum, he can't drop more than his height without having to land on his hands, if he sprints downhill he risks losing control and tripping; things like that.
It reminds me of Dark Souls in that it forces you to be more aware of what you're doing rather than just mindlessly mashing buttons (or in Death Stranding's case, holding forward).
In terms of gameplay it definitely takes time getting used to. It's kind of been reminding me of Dark Souls in the way that it doesn't try to impress you or hold your hand, and is torturous if you're impatient.
And like the Souls series, I can easily see it taking a similar path popularity-wise, being dismissed on arrival, retaining a cult fanbase, and eventually the notice of said fanbase leading to mainstream recognition.
