A strong movie analysis will focus on one particular aspect of the film and go into depth on this one aspect. You may want to review your assignment and see if the teacher is asking you to focus on a specific area of the film. If they are not asking for a particular area, you should select the area you feel you can really focus on and provide supporting evidence.
You might choose to focus on the technical aspects of the film. For instance, the effect of the unstable camera at the beginning of the film. This type of camera angle is supposed to help show the contrast between the capital and district twelve. Since your essay is for a composition class rather than a film class, you may want to focus on a plot aspect rather than a technical one.
You might choose to focus on how the setting is usually in direct contrast with the characters. For instance, district 12 is dark, poor, and broken down. Thus, Gale and Katniss seem stronger and more vital. By comparison, the bright colors and wild costumes of the captial show how out of place Katniss and Peeta are in the games. The decadence of the capital also highlights the insecurities of these two characters and the overconfidence of the career tributes.
Select one area that you want to focus on and make that your thesis. Build your paper around this one point with plenty of evidence and support. A strong paper has a narrow thesis to increase the depth of the paper.