This reminds me of Solaris...
...the Solaris directed by Tarkovsky. Of course, it was not exactly the same, but it left me with the same feeling. It seems like they both deal with one man's journey through loss and regret. I also notice that the same criticism that people had of that movie (i.e. too slow) is the same as what people have of this movie.
I thought that the ending of this movie was heart breaking, and I surprisingly liked this movie.