There can't be a review giving this silent movie any proper judgement. One star is as possible as ten stars are since you are guessing anyway, because whatever version you watch, it is incomplete: The longest version up to date, being merged from Russian and Italian analog material, is still missing 400 m. Especially a dance performance of vanguard artist Valeska Geert is totally lost, among other scenes. And this might also explain why we don't see laboratory scenes of Alraune's making.
So this movie lacks coherence, though the acting of Wegener and Helm is superb and subtle, unlike common silent movies. Still, if you are not (yet) into silent movies or Brigitte Helm's eyes, better start with one that wasn't so much tampered with. But if you'll watch this one, then you are to enjoy a great allegory about humanity being proud of a creation of its own making, then falling for it which works on the destruction of its creator.
So this movie lacks coherence, though the acting of Wegener and Helm is superb and subtle, unlike common silent movies. Still, if you are not (yet) into silent movies or Brigitte Helm's eyes, better start with one that wasn't so much tampered with. But if you'll watch this one, then you are to enjoy a great allegory about humanity being proud of a creation of its own making, then falling for it which works on the destruction of its creator.