The movie is an acquired taste. It takes you back to the time when Heroes were Heroes and villians were villians - save the world and get the girl in the end.
To that end the Movie accomplishes it's goal very well. The dashing handsome clearcut hero is the prime example of good, and he gets the girl who provides witless entertainment throughout the film. All the film effects used in the moving only heighten this sense. It makes for a more comedic film though.
Also, though the film is called "Sky Captain" there are only two aerial battles worth speaking of (Just a note, just because they are flying in an airplane doesn't make it an aerial battle, okay? Aerial battle means in the air...if you've seen the movie you know what I mean).
The plot is fairly intriguing, as well as a bit of dark social commentary. The movie has been compared to Batman, Crimson Skies, and Flash Gordon, and seems to combine the elements of all three.
The best movie to compare it to is the Rocketeer. Its just so similar, and the whole pilot angle comes in as well. Bottom line: if you didn't like the Rocketeer you won't like Sky Captain.
While it's true that in places the movie drags a bit (this is especially true the third or fourth time through the film) for the most part the plot proceeds at a brisk pace. It's still boring, but if you snooze for five minutes you'd better ask someone what continent the characters are on now.
The special effects aren't bad, but occasinally you'll find yourself pointing at something saying, that doesn't look anything near real! If you ask me, this only adds to the comic book effect of the film, but that's just my personal opinion.
If you like literature and studying literature at all you'll love this movie. It's full of cliches, irony and symbolism, if you know what to look for. I liked it, obviously, since I've already seen it four times (Twice on opening day). I wouldn't make a cult following out of it, but it's a pretty good movie.