Writer-director duo Ryan Fleck and Anna Boden, best known for their first feature length collaboration Half Nelson (2006) – the Ryan Gosling-starring heavyweight addiction picture centred on an inner city junior high school teacher struggling with drug abuse and the connection and responsibility he feels toward his students – have strayed a little off piste with their subsequent outings. Yet they’ve found a golden egg in this year’s Mississippi Grind, a tale of two hapless tricksters who find each other late one night in a casino and broker a kinship that leads them on one last journey down America’s great river (doh). It’s grin-inducing, palpable fun – but not without its worthwhile moralistic commentary.

The writing is smooth and persuasive, with quick wit and sparkling charm that make you pine for the mid-western route. It’s the gristly cinematography and boot-stomping soundtrack however, that truly take you there. You smell each bar and taste each bourbon afresh. There’s an irrepressible authenticity you can’t ignore, which temporarily dispels the road-trippin’-by-numbers narrative from ruining your fun – you know, the one where characters eject themselves from their lives momentarily to quench their addiction, only to realise that what they had back yonder was truly worthwhile. A lived-in energy persuades us to float alongside our two anti-heroes care-free, happy with their company if nothing else.

Ben Mendelsohn continues on his untouchable ascent towards best supporting actor in the industry. He delivers one his most complete performances since Animal Kingdom (2010) as the lovable yet pitiful rogue Gerry. He never fails to impress, bringing an effortless authenticity and empathy to his roles. Considering the range within his performance, it’d be a true shock for him not to receive an Oscar nomination come February.

However, Mendelsohn’s quality should not be praised alone. His counterpart, the ever-comely Ryan Reynolds – having recently impressed with smaller, unique projects such as Buried (2010), The Captive (2014) and The Voices (2014) – continues to intrigue with his indie turns. He brings a calm, soothing assuredness as aloof Curtis, the necessary counterbalance to scatty, unpredictable Gerry. Sienna Miller also makes her mark, despite slim screen time – maintaining the second-wave momentum of her career started by noteworthy roles in Foxcatcher (2014) and American Sniper (2014).

A true American road movie, filled with Springsteen-ramblin’ spirit, welcome perspectives on gambling culture and tummy-warming buddy-comedy gold. While it has a lot to say about its subject matter, it’s more the way in which it says it – not heavy-handedly or too hard on the nose – that appeals. It also surprises with its unexpected narrative twists and refreshing character arcs, choosing not to condescend its audience or let the narrative be held ransom by it.

A taught and refreshing State-side indie flick, unafraid to embrace what it is, but more importantly be good at it.