Mélanie Laurent gives an outstanding score, bringing this suspenseful thriller on her own. Laurent’s character wakes up wrapped in a plastic sheet that she painstakingly tears to free herself in the beginning of the film. She quickly learns that she has been imprisoned in a high-tech coffin-like setting. She isn’t entirely alone. She can interact with MILO (voiced by Mathieu Almaric), the onboard computer that provides information. IMDB
The current condition of the oxygen level is the first thing MILO tells her of. It’s at 35%, and her oxygen level is rapidly depleting due to her panic. Director Aja and writer LeBlanc have effectively produced a timer, a ticking clock, until she runs out of oxygen, a stressful situation in which the protagonist must find a solution quickly to survive. But, in order to do so, she must first figure out who she is, how she got into the pod, and where she is.
Oxygen is a well-made movie. When the camera turns on its axis at a moment of perplexing revelation for the character, Aja strengthens the sense of claustrophobia by framing Laurent in often very awkward intense close shots. To highlight moments of fear, the picture pulsates to the rhythm of the character’s quickening pulse. There’s still a game going on about what’s outside the picture.