Female Empowerment
It is extremely unusual for a science fiction adventure film to be driven by a female protagonist, yet Katniss Everdeen is the epitome of a superhero who just happens to be a girl. She is both traditionally feminine and masculine, and does not fit into any gender stereotype or role. She is athletic, strategic, blessed with intelligence and beauty. Yes, there is an element of the traditional heroine in her, for instance, there is love and romance and the suggestion of a relationship; but there is also an ability to fight, to shoot an arrow better than any of the boys, an ability to come out on top in a contest that pits the genders against each other. Katniss is Girl Power 2.0 and this is in many ways the reason for the incredible success of the film.
Distrust of Government
The people distrust the government, and with Coriolanus Snow as president, why wouldn't they? Snow is a sadist and a psychopath, and the welfare of his citizens does not even factor on his radar. The government in the movie are abusing their power, and exerting it for power's sake. They are also powerless to do anything about it, but in an arena where the government is completely disliked and distrusted, rebellion is always possible.
Defiance
Defiance is one of the movie's themes because time after time it is shown to be a characteristic exhibited by the protagonists of the film. Peeta is very defiant, constantly pushing the envelope of what he is permitted to do, and also constantly seeking for ways n which he can defy the authoritarian government. Katniss is also a defiant character; it is her idea to share the poisonous berries between them and kill themselves simultaneously rather than give the nation the fight to the death that they are wanting. This is in direct defiance of what she knows the Government to want and intend.