I saw this film recently with very little pre-knowledge of what to expect, but had been dipping into Central American / Latin American cinema and this was just a constant presence in the background.
The director calls it a 'two-hour visceral scream', which is about right, and I was knocked over by the impact the film had on me...reading this makes me understand why.
The BFI guides come in all shapes and sizes, and this one is an example of when it takes its analysis seriously and really goes into why this film has such an impact. The cultural detail makes a massive difference to the understanding of the film, whilst the technical details about how the colour and sound was used and manipulated was fascinating.
Highly recommended read, but only after you've seen the film, of course...