Running time: 166 minutes.
Starring: Ellar Coltrane, Patricia Arquette, Ethan Hawke, Lorelei Linklater, Marco Perella, Brad Hawkins, Nick Krause.
Director: Richard Linklater.
Released: July 11 (UK & Ireland)
IN 2002, filmmaker Richard Linklater had a dream.
The celebrated Texan director of Dazed And Confused and Before Sunrise, whose mother and father separated when he was seven, wanted to make a drama that realistically captured the bonds between parent and child.
He announced his intention to create a close-knit family of cast and crew, who would reunite every year to shoot new scenes that accurately reflected the physical and emotional changes of the young stars.
Seven-year-old Ellar Coltrane was cast in the lead role and Linklater chose his then eight-year-old daughter Lorelei to portray the central character's older sister.
The result is a directorial doozy of dazzling ambition and scope that falls short in terms of pacing and compelling narrative arcs.
From a technical perspective, Boyhood is a staggering achievement - a testament to Linklater's determination that could have fallen apart at any point in the past 12 years.
From the fragments of each annual get-together, the writer-director has fashioned a naturalistic slideshow of the awkward transition from childhood to adulthood that will doubtless garner an Oscar nomination and a deluge of critical plaudits.
When we first meet Mason Jr (Ellar Coltrane), he's preparing to move house with his mother Olivia (Patricia Arquette) and precocious older sister, Samantha (Lorelei Linklater), who keeps him awake with her rendition of Britney's Oops!... I Did It Again.
Errant father Mason Sr (Ethan Hawke) takes the children ten-pin bowling and the boy pleads for the introduction of safeguards to keep his ball out of the gutter.
"You don't want bumpers - life doesn't give you bumpers," his old man counsels.
Major pop culture and political events including the publication of Harry Potter And The Half-Blood Prince and Obama's presidential campaign allow us to date each chapter as Mason Jr blossoms into a sullen and awkward teenager.
En route, Olivia ricochets from a bad marriage to a drunk professor (Marco Perella) to a bad marriage to one of her students (Brad Hawkins), with occasional appearances from Mason Sr to dispense pithy words of wisdom.
By the very nature of its creation, Boyhood unfolds in fits and spurts, some more interesting than others.
Coltrane starts the film as a cheeky cherub, who is slightly wooden in front of camera, but he grows in confidence and stature.
Arquette has surprisingly scant screen time considering she is primary care giver while Hawke could almost have walked off the set of Before Midnight, given his character's penchant for rambling introspection. The final edit runs close to three hours.
It's easy to be blinded by the glorious gimmick that initiated Boyhood but if you judge Linklater's film purely on what made it to the screen, it's a fascinating yet flawed experiment.