O2 is essentially a survival story where a mother would go to any extent to keep the oxygen flowing for her son while being trapped in a landslide. The story is really good and it is able to correlate the accident which takes place with the environment and how it us taken for granted. And if taken for granted, the nature elements would also “retaliate” and destroy human kind. But the issue lies in its screenplay which is slightly overdramatic especially in the second hour.

The screenplay standing at just 2 hours makes it a crisp watch. This means that the proceedings do not drag much. It opens with a poignant animation sequence which does give you a fair idea about the theme of the film. With a good setup and some interesting subplots, the film was really getting warmed up well. The entire sequence involving the landslide is very well executed and it adds a lot of tension to the drama. With the elements like the oxygen running out to the passengers feeling claustrophobic, it was meant to be a trippy second hour.

But sadly this wasn’t the case. Things start to turn against the film in the second half which lacks clarity of thought coupled with weak execution. The sequences ought to have been thrilling but somehow things literally slide without a trace. The drama is uninspiring and borderline outrageous. While the element of claustrophobia remains intact to the writers’ credit, the over dramatization of sequences leads to its downfall. Somehow the tension was not generated and it lead me to be distracted. Even the emotional quotient of the film did not generate the right kind of emotions. The final act again was quite insipid summing up the screenplay as a lost opportunity.