A movie has to do a million things well to succeed, but sometimes it only has to do one thing badly to fail. Take Gemini Man, in which Will Smith plays an assassin doing battle with a younger, digitally rendered clone of himself: The film is understandably being marketed on the strength of its groundbreaking visual effects, primarily a de-aging technique that has been featured in previous films, but never with such significant screen time. In Gemini Man, we’re looking at a CGI young Will Smith for a solid hour, and he doesn’t come close to resembling a human being. We know what the Fresh Prince looks like, and this ain’t it, so the movie falls apart every time he’s in it.

For the first 40 minutes, before the film dives headfirst into the uncanny valley, Gemini Man is not a total disaster, just the sort of solid action-thriller with big star power that Hollywood used to churn out with relative frequency. Smith plays Henry Brogan, a middle-aged assassin whose retirement is interrupted by his former boss Clay Verris’ attempts to murder him. Verris (Clive Owen) is a megalomaniacal defense contractor with an aversion to loose ends. Brogan and his underwritten love interest (Mary Elizabeth Winstead), an agent tasked with surveilling him who quickly becomes a target herself, must traverse the globe to escape Verris’ team of professional bad guys, which eventually includes the unwatchable Brogan clone.

It’s a fatal flaw born from the film’s wild ambition. Director Ang Lee, who has pushed formal boundaries in Life of Pi and Billy Lynn’s Long Halftime Walk, has a bold, immersive vision for Gemini Man, but it’s a purely technical one. Shooting in 3D and at 120 frames per second, he intends to make the onscreen action feel more real, and he succeeds. Explosions make glass shards fly from the screen, punches land even for those sitting in the last row, and chase scenes put the viewer behind the wheel of a motorcycle as it speeds through the narrow, colorful streets of Cartagena, Colombia. But the approach ends up widening the distance between the film and the audience. You sit in constant awe of the product onscreen, but your awe gets in the way of your involvement.

The digital effects prove distancing, and that could have been avoided if the filmmakers had prioritized substance over style. The younger Brogan, known as Junior, was cloned from Brogan’s DNA without his permission, gestated in a woman we never meet, and raised by Verris to be a younger, faster assassin. Eventually, he teams up with the original Brogan, who gets introspective and decides to pass down some hard-earned wisdom to his younger self. In other words, their relationship strongly resembles that of a father and his estranged son, a dynamic which would have eliminated the need for the awful effects and made Gemini Man a far better movie. A few tweaks to the screenplay, and we could have had a heartfelt action-drama instead of a glorified Sega Genesis game.

But Lee and the overstuffed team of writers and producers weren’t interested in that kind of film. Gemini Man is designed for spectacle not story. It’s meant to lure people to the theater and leave them shaking their heads in amazement at how far technology has advanced. Instead, it might make a Luddite out of you. 

Gemini Man opens Friday in theaters everywhere.