Oppenheimer is about the making of the atomic bomb. The movie not only explains some of the historical framework surrounding the story but also dives deeper into what was happening in the soul, relationships, and legal drama of Oppenheimer himself.
I'm debating on three or four stars here. But my first and most prominent gripe would be the prolonged nudity. If an affair was happening, and it was mentioned or alluded to, then great, I get the point. Now, continue with the story and how it plays an effect on this character. Nudity is never necessary.
Overall it was decent. The dialogue was rich as well as the cinematography. Symbolism throughout was powerful. But if you prefer action over dialogue, you might rate this 2 stars. The film is jam-packed with dialogue. You must force yourself to pay attention to what is happening when they cut from scene to scene. Nolan doesn't make it easy for you to simply passively consume his content. You need to keep up with the complex storyline to make anything of it.
If you are a history buff less interested in all the cinematic effects, you might also dislike this movie. It's all based on a matter of taste, honestly. But Christopher Nolan is the guy who will put much thought into the craft of filmmaking. And symbolism and themes play a heavy role in that taking the first priority while historical accuracy plays second.