TLDR: great game, but your mileage may very depending on how you play games and if the gameplay is enough to hook you. For me, even if it's a relatively short game, the balance between gameplay and plot is off since the gameplay isn't interesting enough to fill the gaps between the narrator bits. Even so, don't worry about trying it out, it has great qualities.
Edit: having now read a summary of the story, I can say it's powerful and very emotional.
Now on my second session, and I can definitely see how this game is meant to be played in 1 sitting: it's very hard to keep track of and absorb the story if you don't. The problem is that while the voice acting is excellent, the sound and visuals give off an amazing vibe, and the plot is cool, the gameplay just isn't engaging enough for me to want to sit down for 3-5 hours. That's already not how I like to play games tho, so it's not completely fair of me, but still. If the story was kept as is but the game made shorter I think I would've liked it more. The story is interesting and I think only works the way it's written now and told in the narrator-style the game does it in, so keeping the game as is but changing the plot/the way it's told wouldn't work. That being said, to reiterate: the voice acting, sound, visuals, and story (isolated from game length) are very well done.