Unfortunately, must of the current Mexican movies are taking the same Hollywood recipe: beautiful actors, violence, soundtracks of well known Latin groups... Batalla en el Cielo does not follow this. The director, Carlos Reygadas, is a person that really wants to show what he has in mind, and does not care about considering distracting elements for having a greater impact in the audience.
I am against the use of sex for attracting audience to a film. However, I really think that some (not all) of the sex scenes of this movie were really part of the story. Also, showing sex as it is (not always as idealistic and esthetic as Hollywood has taught us) is an interesting proposal!
I consider that one of the main achievements of this movies is to show many cultural traits of my country:
-The view of the Catholic religion as a resource to erase the mistakes one has made: "you can do whatever you want, don't worry about the effects because God will always help you"
-The notorious gap between rich and poor people: when Ana refers to Jaime's servant as "la gata" in such a despective -but common- way.
-The double morale managed by Mexican: how can a prostitute, as Ana, can be a moral leader over Marcos's acts?
-The informal commerce (Marcos and his wife sold merchandise in the subway).
-The love for soccer (what can I say about that, if I love it?)
-Cheating on your partner
-The lifestyle in Mexico City, with its traffic jams, way people behave in the subway, neurotic people, kidnaps.
All the issues above are part of the Mexican life.
Personally, I consider the following opportunity areas:
-Not all the music that was used was OK. Sometimes it was too "belic" for me , but at least it is according to the scenes and most of it does not follow the marketing intentions to make you buy a soundtrack
-The audio quality should have been improved (it was not easy to understand, even for people used to the way people from Mexico City speak!)
-Some (very few!) parts were too slow... but considering Reygadas's style, I might think that it is part of his professional charm.
I like to see a different proposal. I would recommend this film to people that, at the time that they leave the theater, really want to think about human nature, rather than thinking if it was an erotic or violent film.
I hope my comment has been useful...