This movie has been out a while, but still I don't want to spoil it. The movie is a faerie story, and as such the tale isn't whats in it but in the telling.
This is a film that's a great example of how to use politics that are radical in a story. You layer that up and you give everyone something to be interested in.
A meditation on the life of the disabled? A meditation on racial hierarchy in 1950s America? A meditation on the virtuous christian male as a (as we would call it today) "Soy Boy?" A meditation on the Alpha male identity and how its used as part of corporate/political/and military hierarchies? A meditation on gay relationships in the 1950s? A meditation on the cold war? An allegory on the Rosenbergs (no really) ? An allegory on the consequences of loneliness? An allegory on the consequences of the lack of intimacy? An allegory about how addictive behaviors can be fueled by alienation? Lots of Freudian symbolism? All of these ideas can be things to rustle up some jimmies.
And its a movie about a woman who has sex with a fishman monster. And that's the most believable part of the fantasy the movie engages in.