‘The Wall’ is a movie that exists mostly as a directorial challenge. Is it possible to make a pulse-pounding war thriller out of a single location and three characters? That’s the type of task that got Doug Liman excited enough to embrace a low budget and pull out all his tricks. It works for the most part, but the movie was likely more fun to make than it is to watch.

Aaron Taylor-Johnson and John Cena star as two exhausted soldiers in the middle of the Iraqi desert. They’ve been assigned to investigate an isolated construction site besieged by a sniper. They find a handful of bodies and no sign of any enemy presence. For the sake of stopping some sweating in the sun, Matthews (Cena) marches out to check the scene and is almost immediately struck down by a sniper’s bullet. Isaac (Taylor-Johnson) races to his aid and catches a bullet in the leg. While both soldiers slowly bleed, Isaac starts receiving radio contact from the mysterious sniper (Laith Nakli). Turns out he’s a legendary bogeyman figure, an Iraqi sniper trained by the U.S. who has been quietly racking up kills without ever being seen. Pinned behind a wall without water, contact to his commanders, and with his partner slowly bleeding in the open, Isaac is forced to use all his wits and training to triumph on the battlefield. All the while, the sniper taunts him on the radio like Dennis Hopper in ‘Speed’.

What we have here is an action film stripped down to the bare essentials. The whole story unfolds on a single quiet location. (A crumbling wall and a pile of garbage are the largest sets.) The villain is a disembodied voice and a quiet hail of bullets without a face. The protagonists are injured and psychologically damaged. Every attempt at conventional rah-rah heroism proves to be a costly mistake. It’s a battle of wits in a genre defined by brute force. On a certain level, it’s a deconstruction of war and action movie clichés. The film is oddly de-politicized for a work of this genre. These are all clever elements of the script by Dwain Worrell (‘Iron Fist’). However, the movie feels slight by design and by accident. It never quite justifies its feature length, playing more like a tense and expertly crafted short film that drags on far too long without a proper payoff.

Doug Liman (‘Edge of Tomorrow’, ‘The Bourne Identity’, ‘Swingers’) delights in using the opportunity to stretch his directorial muscles. Shooting in deliberately grainy 16mm, the director uses every trick in the book to milk the maximum amount of tension out of the concept. Tight close-ups, frantic editing, stretched suspense, blurry visuals, ghastly gore, and wild tonal shifts pile up at a breathless pace. Liman is clearly having fun finding ways of making variations on the same long scene explode to cinematic life. His cast also works quite well, with John Cena proving his limited (yet strong) chops as a G.I. Joe hero over his head, Nakli providing a disturbingly calm villain entirely with his voice, and Taylor-Johnson panting and moaning up a storm as the only actor on screen for the bulk of the running time. The ‘Kick-Ass’ star was given a difficult task in carrying the movie almost entirely on his panicked face, and while he occasionally drifts over-the-top when he has nowhere else to go, he carries the film admirably.

Aside from a few cornball dialogue exchanges and some unnecessarily melodramatic backstory, ‘The Wall’ works brilliantly for about an hour or so. This sort of minimalistic action flick thrives almost entirely on the strength of its cast and director, and the team is strong enough to churn out constant tension with credibility. Unfortunately, the script isn’t heading anywhere particularly interesting. Most of the emotional payoffs are predictable, and while the finale is admirably nihilistic and ambiguous for an American war movie, the production sadly doesn’t quite have the budget to pull it off. The big climax feels oddly truncated and undercooked, which will leave many viewers stumbling out of the theater underwhelmed, even if they were pinned to their seats up until that point.

Everyone involved still deserves points for effort given that this was such a tricky production to pull off. It’s just a shame that they never managed to find an ending worth all the good work it took to get there.