I've always been a huge fan of Alain Chabat, as an actor, a director and a human being. And this movie doesn't change that. He's so talented and so nice, he's been a positive person during all my life since I discovered La Cité de la Peur or Didier. A bit like a French Robin Williams or Bill Murray if I may.
This movie is really good at some point and not that great at some other moments. The first part of the "second act" is the only thing that I really really liked. I could name it "The Waiting", it's funny and beautiful and the idea was awesome. Even the photography is better at this moment of the movie. Can't really tell why !
However, the first and third acts was not so good to me, especially the very end of the movie. I was waiting for more but it ended just like this...
You will probably have Lost In Translition in mind when you start to watch the movie but it's not as good, even if there's a real effort here and once again Alain Chabat is amazing.
About Bae Doona, she's almost like a dream and she doesn't have a lot of lines of dialogue but it's always a pleasure to see her.
Anyway, you should probably watch it and make your own idea. As I said, there is some good in this movie and it's worth watching it.