Blind Alley (El Callejón) is a work of art. Such well made movies don't come by very often.
The plot is straightforward yet works perfectly well. Actually it's a lesson in screen writing.
Ana de Armas shines as an actress, since the whole movie is on her shoulders. She makes you care for the fate of her character. And, of course, she's absolutely gorgeous. The two qualities (great acting and great looks) make her a very rare actress.
The photography is amazing, perfect. Furthermore, it's packed up with very interesting tricks such as multiple perspectives in split screen. These tricks actually help the narrative.
The director and writer, Antonio Trashorras, is someone to keep an eye on, for he surely will do other great stuff.
The music is really good, way above average. Plenty of cool songs.
Some trivia: there are a couple of scenes in which people change their accents, from Spanish accent to Cuban, from Argentinian accent to Chilean, etc. The movie is full of such original resources.
Do yourself a favor and go watch this movie. Even if you're not a horror fan, you'll be delighted.