Cinematography (camera, pace, lighting, angles) is top-notch. Score is majestic and utterly suggestive of a dark, claustrophobic atmosphere and the sense of grappling with the unknown. Acting is good enough. However, the story goes nowhere really. The reach of the plot runs out at just over an hour, once the picture has become clear of what the situation is. From there on, it becomes nonsensical, as it lacks a credible motivation for the main characters' choices of course of action. There is also little reason behind a middle ranked army officer keeping all of this secret from headquarters. And the child subplot is rather superfluous and contributes nothing. The resolution of the story is hasty and fairly commonplace, a sign of the script having run out of original ideas.
The film is, therefore, a mixed bag. Technically, it stands its ground very well against better and more expensive sci-fi productions from Hollywood . It is true that special effects and CGI are sparse here, but this film is not meant to tread the same roads as thinly-scripted, CGI-heavy, teen sensations like Transformers. Instead, a well worked out script would have allowed expert direction to make this into a solid, sober and tense, sci-fi drama.