Some observations: as this was in the early days of film, the actors are legit wearing stage makeup still, which makes Freder in particular look pretty scary to the modern eye. As well, I guess it was a convention of the theatre/silent movies that you over-act to convey emotion and things that would be said normally, which can be seen particularly in Maria's flight from Rotwang. One thing I loved was how Rotwang's whole science expertise was presented as dabbling in the dark arts, kind of like Frankenstein, and having demonic power (a number of pentagrams can be seen). The old creepy connection of science and the occult that people made prior to the 1960s re-imagining of the occult as folkish and mystical still makes for great storylines, as does the old way of filming which turned fairly ordinary, normal building spaces into spooky, evil things with excellent use of shadow and natural, worn features (the 1960s folk occult trend continued this, thankfully).
Overall, an excellent very old movie. To the modern eye, it seems pretty basic, but it provides a window into early cinema and is definitely a different experience from modern film.