At its heart, Hanna is an action thriller that features many of the tropes that go along with that genre: a hero on the run, a ruthless villain, and thrilling fight sequences to name a few. What makes the material fresh, however, is that the hero is a teenage girl, relentlessly trained in a secluded wilderness to be a master assassin. One day, her father/trainer (played by Eric Bana) gives her a choice, and that choice starts the cat-and-mouse game that drives the central plot.
For some reason, the filmmakers decided to add a fairy tale element to the story in that Hanna becomes a very resourceful Little Red Riding Hood pursued by a big, scary wolf. As such, the starkly real locations where Hanna's journey takes her become exotic and dangerous wonderlands. In these wonderlands, she encounters real world issues (like money) made to seem alien and strange due to her secluded upbringing as well as first love (how Hanna handles an amorous young man gives the film one of its only laughs).
As for the big, bad wolf, the story sticks with its fairy tale motifs by having a villain archetype familiar in folklore: the wicked stepmother. In Marissa Wiegler, the movie has a villain who is ruthless and seductive. Cate Blanchett plays Wiegler with a snarling southern drawl obsessed with handling and controlling every situation she encounters. Within the first few moments she comes on screen, the audience knows Wiegler will say and do just about anything to make sure she gets what she wants.
And, this is what sets Hanna apart from other action thrillers. Its story is simultaneously and paradoxically made lighter and more dire with the infusion of fairy tale elements. The viewer is able to access and sympathize with this strange teenage girl as a fairy tale heroine. And, the bitter evil of the villain is greatly heightened as a result, too.
Like I said earlier, Hanna isn't a great movie, but it does provide something more than what is usually found in this genre. Well worth a viewing.