Movie buffs might well choose to write the review in part two. If this is you, make sure you know what you are talking about. Bogglesworld provides a good worksheet on the basic language to talk about films: http://bogglesworldesl.com/lessons/MovieLesson.htm Click on the 2nd link on the left and you have a document you can download and use for reference.
Also think about the language you use to describe it. Normally (if the film is any good) your language should reflect the genre. If you have a spare 3 minutes, choose a genre and brainstorm relevant words and collocations so that you don’t struggle in an exam situation.
Another extremely useful thing you can do is READ some film reviews. You will find many language features including alliteration; something I think I may suffer from.