Well, it's been more than a year since I've watched this movie. It quickly became one of my all time favorite movies, and all this time I loved it just for it's beautiful drawings and animation, never really thinking about it. I consider myself pretty good at analyzing movies, but I never really considered Metropolis was supposed to be deep or anything, it was just a movie made for the spectacle. I was wrong. Like the most complicated works by Stanley Kubrick, it is a movie where even the most insignificant-looking things have a meaning.
As with any movie analysis, it gets easier when you find a lead. Then all you have to do is go through the whole movie in your head with that lead in mind, and everything starts explaining itself. My lead for Metropolis was that you have to see Kenichi (will be calling him Ken from here on) and Tima as Adam and Eve from the Genesis story. Another lead is a more obvious one: that this movie is another sci-fi version of Pinocchio, looking for the meaning of what it is that makes us human.
When Ken meets Tima for the first time, she is at her purest state. Naked from just being born, literally shining. Ken is a very pure character too, and simply offers him his cloak out of politeness. The purity of both characters is confirmed in the documentary on the DVD, as the director explains he wanted the two actors to talk naturally, not act, because they were playing pure characters. The idea of purity in young and innocent characters is an old one in Tezuka's manga. You could say Ken in this movie is a lot like Astro Boy. A hero who wants nothing but peace between everyone and sees no difference between different people.
Tima receiving the cloak is partly because she is already less pure from seeing so much destruction around her literally seconds after being born. It's not an easy world she came to, and it's only the start of it. Ken is also making her part of himself by giving her part of his clothes, maybe the same way Eve was made from a part of Adam? Remember that later in the movie, when Rock asks her who her father is, she has difficulty answering, because Eve was not born from normal parents, but she ends up saying "Kenichi."
Later, Rock starts shooting at them. Ken, as innocent as ever, is as surprised as can be about it. "That guy's trying to shoot us!" He literally doesn't believe someone would actually do this at first.
He and Tima hide with revolutionaries. Ken lies to hide his identity (and is really bad about it). They are now being housed by truly violent people, some who wouldn't mind getting rid of them straight off. The line between friends and enemies is blurred to the fullest here. Atlas makes a deal with Ken, thinking he is a journalist, he asks him to report about their planned success in their revolution. This deal symbolizes the forbidden fruit. They then have a discussion about the upcoming revolution. Atlas says they will destroy Duke Red's Ziggurat, and repeat the story of the bible about the Tower of Babel. He doesn't realize another biblical story is being repeated right now.
Ken goes to see Tima. He has taken the fruit from the tree of knowledge in order to keep her out of harm, and we see the change pretty fast. Tima now knows how to write, she's started using her very first tool (flashback to the bone in "2001: A Space Odyssey"). She thinks Ken's looking at her writing, but he's contemplating her hair, because they've grown from the sun rays, but also because he is suddenly feeling an attraction for her. He compliments her and she get closer to him to thank him. Her chest isn't very well buttoned up. He blushes for the very first time, just as Adam and Eve did when they saw each other naked after taking the fruit. Ken tries to look elsewhere until he remembers he was bringing clothes for her that Atlas offered them. The camera closes in and reopens on Ken with his eyes closed while she's changing. In what seems like a small light-hearted moment, she shows that the clothes are much too large for her. This will have its subliminal purpose later in the movie.
Then, the revolution happens. Ken and Tima don't take part in it (there's a reason the movie skips over it), but they see the after effects. Ken sees an old friend dead, meets up with another who's dieing just as Rock shows up again preventing him to do anything about it. Rock then shoots Ken's uncle. Now Ken, having taken the forbidden fruit, attacks Rock. This is the only time this pure character ever does anything violent in the movie. At his request, Tima takes the gun Rock dropped, her second tool so far. Depicted as an angel throughout the movie via visual clues, she is progressively losing her purity because of Rock's jealousy and man's violent quest for power.
Skip to her finally being captured by Duke Red. As she is trapped inside a room, she uses the only tool she can, a crayon, to write Kenichi's name all over the place. When the servant girl enters the room, she is shocked at the sight, but does not realize that this is a scary reminder of what Tima could have done with the gun, or could cause with an even greater tool: the Ziggurat.
As she later gets on the throne of power, wind very visibly blows her over sized clothes, reminding us how impure she's now become, especially after being shot. She is over clothed, but she is also being overloaded with data from the robots being unnecessarily destroyed by Duke Red. At the height of her inhumanity, right before she starts trying to kill the one she loves, half of her face melts, much like in Terminator 2, but for different reasons: it symbolizes the human-inhuman inner conflict inside her. Her pants also burn up, making her now (almost) half naked. Her pure side is still lingering inside, ready to wake up. When it finally does, she asks "I am who?", not wondering if she's a robot or a human, but if she did the right thing, if she is a good or a bad guy in the end. The answer is she is both, and that's what made her human.
In true Pinocchio fashion, the puppet (doll as Rock calls her) became a real girl in the end, but tragically, she didn't know it.
Reinforcing the both good and bad theme of characters in this movie, Rock is someone that could also have had his own analysis, but it didn't feel as necessary. He's the mysterious character that you can guess your own reasons for his behavior. There is no direct answer to his mysteriousness (though it can be fun to trace his background stories through Tezuka's manga series, notably part of Next World making its way into the dialogue of the movie). There is something however that you may miss if you don't pay enough attention. The heavy political plotting, that serves almost as some sort of background cloud throughout the film, of Duke Red's power reign he is trying to achieve with his Ziggurat tower, was single-handedly stopped by his son, Rock, the most inhuman villain of the whole movie. His reason for becoming the big hero in the end? Because he loved his father. "I can't stop loving you," indeed. That song isn't playing only for Ken. So really, Metropolis is a movie about the power of love.