Everything about Amazon Prime's Hanna indicates it should be more fun than it is. It's adapted from the frenetic, Chemical Brothers-soundtracked film of the same name directed by Joe Wright. It reunites Joel Kinnaman and Mireille Enos on-screen for the first time since the pair starred in The Killing. Its story revolves around a teenaged assassin trained in the woods to kill dudes twice her size with ease. Its first trailer was subtitled with the absolutely wonderful phrase BABY HEIST, for goodness sake. And yet, outside of some tremendous lead performances and a few emotional bright …