One of the best "walking simulators" I've played. The story, characters, voice acting and visuals are all good as others have mentioned but I think the part where it outdoes other games of its kind is, ironically, the gameplay. It really makes use of the unique traits of the medium of videogames to tell its story rather than just being a straightforward linear narrative.
Also, I have to thank it for introducing me to the band Floating Room.