Like most historical movies, Windtalkers can be someone's entry point in learning more about the Pacific Theater of WWII and more specifically, Navajo codetalkers during the War. It does a good job at explaining the importance the Navajos to the US' War effort and even to the Japanese and why extreme measures were made for the Marines to prevent the Japanese from capturing Navajo soldiers.
The action of the movie is really good as expected for a war movie. I don't understand the criticism that critics make regarding this topic (seriously it's making a molehill out an nonissue). I liked the soundtrack for this movie, the theme is very good.
What most people have a problem with this movie is understandably the characters, specifically the main protagonist, Nicolas Cage's character. Where the major character focus should have rightfully been Adam Beach's character (Ben Yahzee) one of the two Navajo codetalkers in the movie, the writers went with Cage's. What could've been a decent war flick, is turned into a somewhat controversial film all because of poor character choice in terms of whom the plot should follow.
The character development for most of the cast is great through.