Tonally aiming for somewhere between Zombieland and Bourne, American Ultra has a concept that seems ripe for fun on the page, but fails to deliver on the screen. Screenwriter Max Landis (Chronicle) and helmer Nima Nourizadeh (Project X) both suffer the Hollywood sophomore slump, and their film never really gets going.

Jessie Eisenberg is a our neurotic, stoner hero Mike, who suffers from anxiety issues and is stuck in a one road town. On the plus side, he has a super hot, endlessly understanding better half in the form of Kristen Stewart, so all good, right? Well, yea, pretty much... until two government operatives attempt to kill him and murders them both dead, without even realising he had the skills to do so. Y'see Mike is a universal soldier of sorts, and was part of a failed program by the CIA; he's just been reactivated by the former CIA superior who recruited him, in order to save his life.

It's a high concept sounding flick, with a barrage of quirky characters and plenty of opportunities for fun. Given how Eisenberg has managed to walk the tightrope between two genres before with Zombieland, he's seems the perfect choice for Mike. The problem is not even camera trickery can make him look like an action hero. Sure, we get that the joke is partly how scrawny Mike is, and how he could never take on so many tough henchmen, but when the action does happen you don't buy it, not for a second.

It is incredibly violent, all be it in an almost cartoonish fashion; but the action that precedes the violence is rarely visceral or well staged, and the whole thing feels strangely vacant as a result.

Stewart proves once again what an amiable presence she is on screen, while Walton Goggins, John Leguizamo and Topher Grace go balls to the wall in search of laughs - but the film falls flat.

There are a couple of fun moments towards the end, but overall it's a missed opportunity given the intriguing concept.