Much better commentary on violence, accountability, and actions than you see in FPS's like Spec Ops: The Line, or Bioshock, or whatever. Only takes you four or five hours.
Forget all the comments on the music and gameplay and mechanics. Those are all well-executed, but the beauty is in the story, writing, and symbolism. Queue our "game is art" crowd. Maybe not quite art, but if mind-bending movies that use symbolism, alternate viewpoints and time-skipping as narrative techniques to blow your mind at the end have ever impressed you, this will not disappoint.
Also, if you loved the movie Drive, this game will remind you of it intensely.
It's rare when a game stays with you all day after you finish it, then you think about it while you're trying to sleep, then you start thinking about it when you wake up.
This is a game that really pushes the medium forward.