The whole story happens inside a fortress. The characters can only rely on their wits, their strength, their training and their sense of psychology. The psychological manipulating is well done and expresses the stressful situation and the dangers. every minute counts and every person must be carefuly handled. The plot is written as a comedy but it is not really. Many decisions are hard.

The acting is solid. The idea that we watch the story unfold in, more or less, real time, makes us feel the suspense and the risks.
The filming is quite theatrical and it is sucessful.