Despite the icon used here, this is actually the first time I've seen this film. Previously, I had only seen the anime remake, Metoroporisu (2001), which is absolutely stunning in its own way, but so different from Metropolis that it's almost better viewed as being simply creatively inspired by the original, rather than actually being a remake of it. I have wanted to see the original for years, though (hence the icon). I've read quite a lot about it online, and was pretty certain I would love it.
Thankfully, the film entirely lived up to my expectations. I can really understand now why it is considered so important, particularly in terms of cinematic style and techniques. Its scale and scope are so ahead of its time that it often felt like I was watching a much more modern film that was merely imitating the stylistic character of 1920s cinematography - like the film of Call of Cthulhu which I saw recently. I suppose the real message there is that I shouldn't complacently underestimate what people were capable of doing in the 1920s - as it is very easy to do, especially in the context of a genre that was relatively new at the time.
High points included Brigitte Helm's magnificent portrayal of both the Real and the False Marias - histrionic, of course, in keeping with the style of the time, but showing a great range, and doing a marvellous job of bringing out the Virgin Mary and the Whore of Babylon inherent in the two characters. I am astonished to learn now from the IMDb both that a) it was her first ever film role and that b) she gave up her film career only eight years later - partly due to the coming of Nazi Germany, but obviously not entirely, as she had already been offered roles in America before then. I also enjoyed the use of allegorical visions - for instance, Feder seeing the Heart-Machine as Moloch the destroyer, the dial he is labouring over turning into a gigantic ten-hour clock to represent the tortuous length of his shift, or the montage of lustful eyes which appears around the False Maria as she dances seductively in the night-club - very much à la Josephine Baker.
Perhaps most importantly, though, I'm now in a much better position to appreciate other works of cinema for having seen this: 1984, for instance, almost any Frankenstein movie, or Dark City. I feel like I've been handed a missing piece of jigsaw puzzle - though of course the output of human creativity is so great that no-one could ever hope to see the whole picture.