Fernando León de Aranoa’s latest feature chronicles the odd and frequently unexplored lives of foreign aid workers. It’s a messy and tonally inconsistent little flick. However, in this particular case that’s not necessarily a criticism.

The movie goes for a darkly comedic look at the madness of offering help in a war zone, where all the best intentions are crushed by mind-numbing bureaucracy and people need to joke at their impossible circumstances to remain sane. The director claimed that he’d never seen ‘M*A*S*H’ before making the film, but I don’t believe him (once again, in a good way).

Benicio Del Toro takes on a rare good guy role to play a foreign-aid worker stationed somewhere in the Balkans in the mid-1990s. He opens the movie attempting to lift a (particularly fat) corpse out of a well before it starts to rot and permanently contaminates the water. The rope breaks almost instantly and the ironically titled movie then follows him over the next 24 hours desperately trying to get a replacement rope. Helping him out is a naively idealistic new worker (Mélanie Thierry) and a loud, brash and charming obnoxious old buddy (Tim Robbins). Their personalities bump up against each other in all sorts of ways both good and bad while bumbling from one failed solution to the next. Conversations fluctuate from comically banal to overtly philosophical. They pick up a young boy destined to be dangled in danger as well as a UN evaluator (Olga Kurylenko) who happens to be Del Toro’s jilted ex. All the while, the threat of violence hangs over the outsiders, like a ticking time bomb just waiting to explode.

Based on a novel written by former Doctors Without Borders president Paula Farias, the film boasts a palpable authenticity amidst all the one-liners. It works best as a cynical satire of bureaucratic nonsense that makes any sort of politically sensitive aid work impossible, as well as a rambling hangout movie between a pair of buddies worn-in like old shoes. The filmmaker wisely keeps things loose and playful, while keeping the audience constantly off- balance. Most of the dialogue not spoken in English (and there’s quite a bit) is played without subtitles to deepen the audience’s confusion. Scenes like one involving Del Toro being told a store doesn’t sell rope while he’s holding rope in his hand are both surreally comedic and laced with a certain dreadful tension. The movie might primarily be a comedy, but it never ignores the reality of the situation, and de Aranoa creates an uneasy tone punctuated with violence and tragedy only when necessary.

The major pleasure of the film comes from watching Benicio Del Toro in a particularly playful mode. He disappears into his wayward and charming character, his typically weighed-down eyes often widening for a smile. It’s easy to forget how charming the guy can be given his predilection for playing nefarious scallywags and he carries the film nicely. Tim Robbins is almost as good, but not quite. He’s essentially playing a hippie cartoon of a character, but he gets the joke and invests the guy with more heart and warmth than might have happened otherwise. Both Mélanie Thierry and Olga Kurylenko are decent, but sadly their roles are nowhere near as complex as the boys’.

Sadly, other than Del Toro’s wary world traveler, most of the supporting characters are more symbols and plot devices than humans. Individual scenes unfold with a breezy naturalism, but the writing is just a little bit more arch and pointed than it thinks it is, often to the film’s detriment.

‘A Perfect Day’ works best when pitched for dark humor and rambling authenticity. Whenever things get too dark or the director tries too hard to make a point, things tend to get a little rough. Thankfully, de Aranoa doesn’t indulge in message-making or shock tactics too often. He’s wise enough to know that his film is all about the ramble, and that’s likely how he was able to get some famous faces to fly across the world with him. He has made a fun and intriguing film about a worthy subject. It might not be a masterpiece, but it’s worth the trouble of seeking out. Madness-of-war comedies like this are incredibly difficult to pull off, so even a decent entry in the genre qualifies as a mini-filmmaking miracle.