If your summer holiday entertainment menu is in need of a colourful kick up the arse, Bullet Train comes barrelling into cinemas this week. The Japan-based comical caper – weaned on a diet of liquidised Guy Ritchie mockney monologues and lesser Statham Transporter fights – might be as woefully Westernised as its influences sound but there are worse ways to kill two hours.

Returning to his deadly day job after a period of self-reflection, Ladybug (Brad Pitt) is feeling ambivalent about the whole gun-for-hire biz. To the extent that he’s reluctant to pack a piece at all. But his honey-voiced handler Maria (Sandra Bullock) persuades him to step into the shoes of a colleague from the assassin community who is off sick with a dicky tummy. Board an iconic train, grab a case, deliver the case, and pocket the fee. How hard can the assignment be?

Double hard bastard hard, as it transpires.

Ladybug’s opponents are introduced as he obliviously wanders down the aisle. Bickering Brit bruvs Lemon (Brian Tyree Henry) and Tangerine (Aaron Taylor-Johnson) are claret and blue through and through West Ham fans with a crime boss’s son and ten million dollars to deliver at the end of the line. The Father (Andrew Koji) is ready to face off with the killer who hospitalised his son, the elusive Hornet (Zazie Beetz) has a predictably lethal sting, The Wolf (Bad Bunny) is having a TERRIBLE day and The Prince (Joey King) has daddy issues. And one very bad man has brought them all together.

Their backstories are a mixed bag of comedy and tragedy with a sprightly soundtrack and some familiar-feeling gimmicks doing a lot of the heavy lifting that smarter writing and tighter editing ought to provide. As their commissions intersect, the hitpeople (hitpersons?) become moderately more interesting. A seated briefcase slap fest in the quiet car and a bar car brawl are two particular highlights, though even they lack panache and enough heart to fully engage.

To become the thing it aspired to be, Bullet Train needed to lean further into the absurdity and let the darkness in. Director David Leitch and screenwriter Zak Olkewicz had rich source material to plunder when they chose to bring Kôtarô Isaka’s satirical novel Maria Bītoru to the big screen. They were faithful to many elements and quirks yet something was clearly lost in translation. The film’s insubstantiality and misjudged tone recall Lucky Number Slevin, another ultra-violent black comedy that pulled punches and failed to live up to its potential.

Someone could have mentioned that it was weird to do a Punch and Judy joke when Weekend at Bernie’s was ripe for the picking. The jabs at Japanese culture could have stayed on the page and the script been shared out more evenly. Poor Pitt’s reassuringly square shoulders cannot carry an action movie alone. Brad might be charisma personified but even in his woefully short time onscreen Hiroyuki Sanada (as The Elder) delivers a masterclass in being effortlessly cool and artfully fatal, leaving Hollywood’s leading man looking guady by comparison.

The Shinkansen railway network is an inarguably interesting backdrop for an action movie. Effectively locking five assassins inside a bullet train and setting them on a collision course should be a recipe for an exciting two hours at the cinema. The starry cameos are an undeniable crowd pleaser. And dishing up Brad Pitt as our tour guide through the carnage? *Chef’s kiss* Therefore it saddens us to say that Mr Pitt’s charms failed to save the day. Entertaining it might be but, despite sleek looks, Bullet Train meekly chugs along like a National Rail locomotive approaching fallen leaves on a tarnished track.

Bullet Train opens across UK cinemas on August 3rd