At times it can be dark, but I believe it is underrated because of the sci-fi core aspect. I can only imagine my wife watching this and getting a glazed look in her eyes not understanding the concept.

A lot of sci-fi gets ignored because of this. People just can't or won't immerse themselves in it.

Your right, Spielberg really pulls back and let's the actors take control of script. Beautifully shot and just a blast of entertainment.