Making half an argument makes half a story.
Kinetic, pulsating and well-paced for sure. Emotionally compelling? Not so much.
Hanna fails to tell a complete story and thus, quickly becomes forgettable the moment one leaves the theater. The Objective Story and Main Character throughlines are solidly illustrated (though the latter required a bit more development and concrete thematic issues), but the other half of a meaningful story--the Influence Character Throughline and the Relationship Story Throughline that develops between Main and Influence Characters-- is nowhere to be found.
There are some potential candidates, the young girl she meets being one, but they aren't used effectively to say anything about the events that happen on-screen. In reality the best choice would have been Marissa (Cate Blanchett). Not only because of her star power and ability to pull off an emotionally complex character, but also because the issues unique to her character--her need for things to be orderly--would have fit in nicely with the thematic issues surrounding Hanna herself.
Worth the rental or Netflix showing when available.