The Imitation Game isn’t A Beautiful Mind. But it wants to be. Unfortunately, it isn’t.

The Benedict Cumberbatch-starring movie is garnering critical praise and plenty of awards, but it’s not all deserved; despite being based on an incredible true story and featuring an Oscar-worthy performance by its star, the movie rarely hits its stride.

The Imitation Game is about Alan Turing, an eccentric mathematician and cryptographer who was tasked with breaking Germany’s Enigma machine during World War II—the result of which was estimated to have shortened the war by at least two years. Despite being a war hero, Turing was also persecuted for being gay—at the time, homosexuality was still illegal in the U.K.

Turing’s life and achievements truly are incredible, and his ultimate fate quite sad. In other words: his story was ripe for a major film adaptation.

The Imitation Game is decent but unremarkable. Directed by Morten Tyldum (Headhunters), the movie has the components to be successful but they never entirely gel together. The storytelling is at times clunky; Tyldum dwells on certain things for too long and skips over other aspects of Turing’s life, resulting in a far-from-smooth experience.

The decision to tell the story out of chronological order—by having a nosy police officer investigating Turing in the 1950’s as both a narrative device and a means to connect two different parts of his life—was a bad one. The film’s primary focus and the one that takes up the vast majority of time is Turing’s attempts to break the Enigma machine. This area of the film largely works, and should have been what the movie was all about.

But it’s not. The movie is also about the persecution by the government due to Turing’s homosexuality. This “add on” story doesn’t work as presented. While Turing’s death is an important aspect of his story given the circumstances, the way Tyldum so rapidly swings the story away from the Enigma machine to one about homosexual oppression is jarring. It doesn’t help that the more interesting story climaxes halfway through the third act, a move that causes the film to stumble its way to the finish line.

Despite its flaws—and they are serious flaws—The Imitation Game features an absolutely incredible performance by Benedict Cumberbatch. He is at the top of his game here and should be considered a frontrunner for Best Actor. Keira Knightley is also strong in a supporting role.

The Imitation Game has plenty of positives—most notably the acting—but tonal shifts and clunky storytelling keep the movie from being the juggernaut some consider it to be. The movie bears a lot of similarities to the Oscar-winning A Beautiful Mind. Unfortunately, it’s not nearly as good.

Review by Erik Samdahl unless otherwise indicated.