It’s like three films in one, first a mystery, then a drama, and finally something bordering on dark thriller.
While it pulls off these different sections, the consequence is that the film is *very* long.
Matt Damon’s character is the constant in the film. He’s very understated, to the point that you hardly see his face for the first hour because of the baseball cap. But I did buy his choices, and especially towards the middle of the film he opens up and steals the screen.
The clash of his outlook with that of those he meets is more or less the purpose of the film. He’s put in this impossible situation, completely outside his comfort zone, and just has to deal with it by relying on people he would never have met in his regular life.
The other elements, including the plot, are really secondary. If you want to watch two and a half hours of (well done) cultural dialogue then this is the film for you.