The anime takes place in 1914. The threat at the start of the movie isn’t another invasion but a looming break up in the world defense force due its European members being recalled back to their home nations to fight in the Great War. The fear among the leadership, Teddy Roosevelt, is that a divided Earth would make it vulnerable if attacked again. It’s not a spoiler to say that another invasion does take place, which is the point of the anime.
There’s a lot of good stuff in this anime. I thought the CGI is excellent. I loved the look of the technology, both the human and the Martian. It’s all very realistic and believable. Just what one would think if humanity of the early 20th century had tried to fuse alien tech with human.
Another great aspect is the action. The battle sequences are fast paced and lots of fun.
Of the characters in the movie, their portrayal of Teddy Roosevelt is my favorite. I loved it when during the attack on New York he picks up a giant machine gun and started fighting the Martians to defend New York. The anime character was just what I would have thought Teddy would have been like in that universe.
However, this anime is far from perfect. One criticism I have is the art of the characters. They drew the men to be these bizarre, muscle-bound freaks where the muscles move and bulge in ways that are, I guess, anatomically impossible. Very odd and grotesque.
Several scenes appear stolen from other movies. The air battle between the biplanes and the Martian aircraft was blatantly taken from Independence Day.
Finally, is this movie steampunk or dieselpunk? The movie promotes itself as steam. However, it does have airplanes, which are standard diesel era tech. The vehicles operate on a hybrid of steam and internal combustion. In addition, steam tech, such as locomotives, was used well into the 50s. I rather think the creators called it steampunk because 1) they were unaware of dieselpunk, 2) they think any steam tech makes something steampunk, or 3) they simply stuck the label on it as crass commercialism. Regardless of their reasoning, I would call this movie dieselpunk.
Is this a great anime? No. However, it is a good anime and I would recommend it if you want something mindless to have on.