I don't think there will be much surprises, at least not for what it's aiming at. I don't think that people who watch the first 10 minutes of the movie, will not know where this is heading. But it's about the journey and not about the goal. And the journey is a quite decent one, if you think about it.
It's nicely acted, there are nice points along the way, good story moments here and there and the weird moment occasionally. While mostly it plays at one location, it does have to offer a few other things. Still you will not get any great visuals, if you are looking for some. I think that this would work better as a book (maybe it is/was already one?), but the makers of the movie did a nice job, if you like this sort of movies