American Ultra follows the story of two stoners, Mike (Jesse Eisenberg) and Phoebe (Kristen Stewart). Mike works at the local convenience store and spends his free time smoking weed or doodling the adventures of a comic book character he's come up with. On a seemingly uneventful night, he's visited by a member of government, Victoria Lasseter (Connie Britton), who makes an attempt at "activating him." It doesn't appear to work at first, but after two thugs try to blow up his car, his hidden secret agent skills are activated and he kicks some ass. Using soup, a spoon and, eventually, a gun, he kills them both, starting up a series of frantic events involving everything listed in the first paragraph. It's one chaotic movie and it's a lot of fun.
As we travel down the rabbit hole, we're provided with a much deeper film than one would expect. It's not trying to say an awful lot, nor is it trying to win any Oscars, but it's got a surprising amount of heart to it, managing to create some extra stakes when it comes to the more intense action sequences. There's a solid relationship built up between Eisenberg and Stewart, and as the film begins to unfold itself, this relationship is given more layers than you'd predict. The film manages to become more than just your average stoner romp. It's no Inherent Vice, but it's fun.
That being said, this does result in more than a few tonal shifts. While each of the individual scenes plays out excellently, as a whole they're a bit everywhere. There's action, there's romance and there's comedy, and while it can from time to time play off smoothy, it can also create a few bumps in the road, especially when the comedy aspect drops the ball a little bit. These many tonal shifts, unfortunately, lower the overall energy of the film, but by the time the third act comes around the film is just balls to the wall crazy and it's a blast.