If you're going to make a comedy-drama about elderly gangsters – this could have been called Oldfellas – then Al Pacino and Christopher Walken would be on any shortlist for the cast.

Not only do they bring all that iconic heft, but the fact that each of them still seems viable with a gun in his hand speaks volumes about their calibre.

Stand Up Guys may not be the edgiest subject of the week, or the hippest. But with Pacino and Walken together for the first time, joined by Alan Arkin – never much of a hood, but a grumpy old man par excellence – this feels like the one that shouldn't be passed up.

Pacino plays Val, a con at the end of a 28-year stretch, proceeded out of prison by a pensioner's pot belly. He's met at the gate by former fellow robber and best friend Doc (Walken), who has been making a more conventional segue into old age, mostly alone in his tiny apartment, or painting, or making the same orders in his favourite diner.

Doc needs to shake himself down if he's to provide the coming home party that the rambunctious Val demands (bars, dancing, brothels, the usual clichés, each given a tasty twist by the simple fact of their ages). But he has another, more pressing, matter on his mind: the order by the local gang boss that he kill Val within a day of his release – payback for a perceived wrong all those years ago.

As the pair spring their old getaway driver Hersch (Arkin) from a rest home to join them in their high jinks, this becomes one of those movies driven by time – the clock ticking on Doc's deadline, old age catching up on everyone, nostalgia fuelling their last night together.

Thankfully, the film itself doesn't become maudlin. The tone of Noah Haidle's script is a perfect balance of comedy and pathos, underpinned by danger – and hope that the pensioners can turn the tables on the younger hoods. There's material here that is regrettable, borrowed from other films about old friends past their prime; the running joke involving Val's over-eagerness with Viagra will pain those who cling to memories of Pacino's prime.

But the pleasures outweigh such moments. Haidle has a great ear for dialogue, the delivery of which is sublime. Only Walken would choose such stress when talking of his life as "nothing earth-shattering". And the diner conversations between he and Pacino are the laidback equal of the showdown between Pacino and De Niro in Heat. Physically, they play like a sort of Laurel and Hardy, with Arkin a terrier sniping around their heels.

Actor, documentary producer and only sometime director, Fisher Stevens belies his inexperience behind the camera with solid, nicely paced work, perfectly attuned to his actors. The film doesn't go out of its way to sugar-coat characters who, however honourable within their code, are still criminal. Adding humanity to the mix, and balancing the elderly leads, are able young actresses – Julianna Margulies as Hirsch's daughter and Lucy Punch, typically, wonderfully weird as a woman who has taken over the family business as a brothel madam.