The movie is smoothly put together. The narration is told in multiple interweaving strands with at least two layers of retrospection, as in every Nolan movie, but it is easy enough to follow -- at least if you have been reading Manhattan Project history for four decades.
There is a lot of atomic fanservice, with many of our favorites such as Szilard, Fermi, and Feynman shown (and in the case of Feynman, caricatured) briefly.
There is even “Jewservice”: Oppenheimer is presented as more open about and concerned with his Jewish identity than he is usually portrayed, while his sense of his own Jewish and American identities is challenged by Rabi, by Einstein and by the film’s main antagonist, Lewis Strauss.
To understand the film one has to understand the Oppenheimer character's complex, changing, and even contradictory views of the politics and morality of nuclear arms and nuclear war. One also needs to decide whether Nolan, usually more explicitly didactic, wants us to think that his Oppenheimer is right -- and, if so, which Oppenheimer is right.
Spoiler alert: when you see the flash, cover your ears.
