Rapper Tupac Shakur was a revolutionary, a controversial, brilliant artist cut down in his prime, who only became more iconic after his death. The son of a Black Panther, a high school chum of Jada Pinkett Smith, and a vanguard of West Coast gangsta rap, Shakur endured, and produced, far more in his 25 years than most ever do, and his life story has been overdue for the biopic treatment, especially in light of the films about his rivals and contemporaries such as “Notorious” and “Straight Outta Compton.” After a long gestation, “All Eyez on Me” arrives in theaters, directed by Benny Boom, but this disorganized biopic isn’t quite worthy of its subject’s remarkable life.

Playing the part of Shakur is newcomer Demetrius Shipp Jr., who looks eerily like the rapper, channeling Shakur in a performance where actor and real person ultimately meld together. Especially once he gets into his performance flow, the physical comparison is uncanny, in his bobbing, lanky-limbed dance movements and head-swiveling delivery. In recreations of television interviews, Shipp nails the energetic, motor-mouthed cadence of the outspoken Shakur.

But the film surrounding Shipp is rough going. “All Eyez on Me” gets off to a very bumpy start, as it skitters wildly from life event to life event, dates, locations and story-framing devices pummeling the screen. We’re given a flash forward to Tupac onstage in front of adoring fans, then a prison interview that serves to guide us through his childhood and early career. It’s just lazy screenwriting to plop in an interviewer to interject names and places rather than establishing these facts in the script, and the seams are painfully obvious.

The first 45 minutes of “All Eyez on Me” never gels, with bizarre scene transitions and characters that are scarcely introduced. It feels like much was left on the editing room floor, though even more could have gone. The film only finds its legs in the second half, as Tupac becomes caught up in drama with Death Row Records, Suge Knight, and the East Coast/West Coast rap beef.

The problem with biopics is knowing what – and what not – to include, and the writers of “All Eyez on Me,” Jeremy Haft, Eddie Gonzalez and Steven Bagatourian, erred on the side of more is more, rather than selectively choosing the events that would best express the life story of the film’s character.

Director Boom never met a dramatic moment that he didn’t want to milk the life out of with an on-the-nose gospel song, or a swirling steadi-cam movement circling Tupac as he comes to a revelation. Subtlety is not his strong suit, and he seems to have been telling his actors “bigger!” all the time. Danai Gurira, playing Shakur’s mother Afeni, reaches especially operatic heights.

Tupac was a complicated, nuanced person. Raised by a militant African-American freedom fighter, he recited Shakespeare in art school, and witnessed the ravages of drugs on his family. He found a voice in gangsta rap, but he was more than just “thug life,” and saw his music as a message of black liberation. That complexity is flattened out, and comes off as inconsistent in this film. While it’s a delight to watch Shipp channel Tupac, ultimately, the imitation doesn’t come close to the real thing.