SPOILER ALERT!
I liked the plot twist. Like, you'd not guess that he was the guide to the afterlife (or at least in my theory, he is) actually that easily and not think he's just a man who escaped psych ward.
I would genuinely like a sequel about his plans for the ending D, though. Since it kinda left us on a cliffhanger on why he needs us, in my opinion. Loved it, still.