It's as though someone took the best of Spielberg's early films and put them in a blender (Close Encounters, ET, and a little bit of Jaws) and then added Alien for taste. The film has a great cast of young'uns, especially the Elle Fanning, who could easily be be nominated for Supporting Actress for two of her scenes. (It's awfully hard for someone that young to be aware enough to give a performance that has three layers at the same time.
I was afraid that the self-reflexive nature of the film would get in the way, but the movie-within-the-movie was not at all a distraction, although the child director seemed to have been discarded as a main character halfway through.
Kyle Chandler is a little goofy (his part is not very well written). And there are a lot of "refrigerator moments" as Hitchcock used to say, where later that night you think about plot points that don't make sense, but in the flow of the movie they are fine.
Definitely worth a rental if you have not seen it yet.