ANN; IMDb; Rotten Tomatoes; Sony Pictures; TV Tropes; Wikipedia
Caution: potential spoilers.
This is of a science fiction subgenre called "steampunk," which I've heard of and always thought was a cool concept, though I've had rather little exposure to it, I'm afraid. The movie is computer-animated, though it looks more like traditional animation, to me. At any rate, it's quite nice to look at. As far as story goes, I felt like I was having a bit of trouble following it, though I may have been wrong about that. Having finished the movie, I rather feel any confusion was... well, not quite my fault. I think perhaps I was simply expecting it to be more complicated than it was. It felt complicated, but it probably wasn't. Still, I guess I liked the movie well enough, once it really got going. It just wasn't as good as I might have hoped.
Anyway, it begins in Alaska (Russian America) in 1863. There's an experiment involving highly pressurized steam, being conducted chiefly by father and son scientists Lloyd and Edward Steam (I assume their surname is just a wild coincidence, right?) They're working for a company (I think it was an American company) called the O'Hara Foundation. Anyway, there's a terrible accident in which Edward is apparently killed, caused by Lloyd's pushing the project too far.
The story then flashes forward to 1866, in Manchester, England (where the Steams are from). We meet Edward's son, James Ray Steam (who goes by "Ray"). He works in a mill which of course also involves steam power, and he also works on steam contraptions at home. He obviously takes after his father and grandfather. Which seems to be something local boys like to tease him about (they say his father and grandfather are crazy). Um... and soon we meet a girl who at first I suspected might be a potential love interest for Ray or maybe just a friend, but later it seemed she was actually his sister. (Now that I'm writing this review, I looked at Wikipedia, which says her name was Emma and she was his cousin, which facts I failed to pick up on while watching the movie.) They live with Ray's mother, and Emma's brother Thomas.
Well, we don't get to see alot of them. Before long, a package arrives from Ray's grandfather, with instructions not to let anyone get their hands on the contents- a mysterious metal object called a "steamball." The letter especially warns to keep it away from anyone from the O'Hara Foundation. But two men from the Foundation arrive wanting to get the steamball, which they say is their property. Then Lloyd himself shows up, informing his family that Edward is dead, and he does his best to hold off the Foundation men while Ray tries to get away. If I recall correctly, Lloyd told Ray to take the steamball to Robert Stephenson, a fellow scientist. Though later in the movie I got the impression he hadn't wanted Ray to do that. I dunno, I'm a bit confused on this point.
In any event, Ray uses one of his contraptions to try to escape, but the Foundation men have a much more elaborte steam-powered contraption they chase him in. But then Ray is helped by a man named David, along with his employer or colleague or whatever, who happens to be Robert Stephenson. Though just when things seem safe, the Foundation men return with an even greater contraption, as well as a zeppelin, and manage to kidnap Ray and the steamball.
He's taken to their steamcastle, in London, where we meet a girl named Scarlett, the granddaughter of the founder of the O'Hara Foundation. She's rather spoiled and snobby, but she has her nicer moments, and it does seem as if she likes Ray. Sort of. (I think Ray's feelings about her were somewhat mixed, as well, but at least she's pretty. Though I don't see much difference between her appearance and Emma's. In any event, I guess she's a vaguely potential love interest for Ray, though nothing ever really happens, though he does save her a few times... she has a tendency to ignore danger, perhaps thinking herself immune to any harm, because of her status.) I dunno, it was hard for me to get a bead on her, per se... it's not like she had a straightforward progression of character development, it seemed more back and forth, to me. She could be concerned about human life or the evil things the Foundation was doing, but she never seemed to stop caring about money or status, either. Anyway, we also meet Archibald Simon, a representative of the Foundation whose duties seem to include taking care of Scarlett, and overseeing things on the steamcastle, and making a sales pitch to potential foreign investors. But the most surprising person Ray sees in the steamcastle is his father, who isn't dead after all... though he has had some of his body parts replaced by machinery, after the accident.
Well, Eddy is still working for the Foundation, though Lloyd is against them. Ray, of course, is caught in the middle. He loves them both, and doesn't want to believe either of them would do anything wrong. He works for a time with his father, in preparation for the upcoming London Exhibition, with new scientific developments from all over the world to be introduced. The steamcastle, of course, far exceeds any of them. Anyway, I guess the Foundation had created three steamballs, though I think the first two were far larger (like room-sized) than the handheld one Ray had. But while each is immensely powerful on its own, all three are required to properly (and safely) power the steamcastle.
Meanwhile, Stephenson and David will also be at the Exhibition, and they seem to be working with a British admiral. They're not happy about the O'Hara Foundation (known arms dealers, apparently) being granted entry in the Exhibition. Well... eventually the Exhibition becomes a warzone. It seems the O'Hara Foundation launches an attack, as a demonstration to the investors to whom Simon is pitching the steamcastle and other inventions. It really was rather amusing how he never stopped the sales pitch no matter what happened (aside from taking the occasional moment to show vague concern for Scarlett's safety).
Anyway... there's alot of debate between Lloyd and Edward about the nature of science and its role with helping humanity, and all that. I think Eddy's point of view is much the same as Lloyd's was before the accident, and even now their views aren't that different, aside from Lloyd being completely against creating weapons. And using science for financial gain. Actually I think it was just the Foundation that was interested in money or weapons. I think they were using the Steams, but at the same time, Eddy was using them (without any moral reservations about what was done with his work). Then of course we have Stephenson and David, who may not be any more benevolent than the O'Hara Foundation. Yes, all the scientists had similar views about science, and I think they all had principles, actually... but each individual had his own ideas about how to achieve those principles in the end, and what they were willing to sacrifice along the way. So of course... everything was confusing for Ray, who never stopped loving both his father and grandfather, but also never abandoned his own principles.
And then he became a superhero, kind of like The Rocketeer. The end.