What's better than Will Smith? Two Will Smiths! In new action thriller Gemini Man, where there's a Will ... there's another Will. Yet this technology-driven movie ends up much, much less than the sum of its parts.

Gemini Man's big selling point is that the film features Will Smith as both an aging assassin and the younger clone sent to kill him. It's an intriguing idea, and the effects absolutely knock it out of the park. It's genuinely impressive when Smith as we know him goes face to face -- and even hand to hand -- with the digitally de-aged mid-twenties model.

Enlarge Image Gemini Man

Combine that with Oscar-winning director Ang Lee's choice to use 3D and a higher-than-usual frame rate, and you get a movie that shows off lots of interesting moviemaking technology. Unfortunately, it ends up as an unengaging tech demo, because the characters and storyline seem to have been given barely a fraction of the thought that's gone into the effects.

Smith plays government assassin Henry Brogan, who's looking to retire when his agency decides he'd be better off dead. So he goes on the run, picking up a plucky passenger in the shape of Mary Elizabeth Winstead doing her best with very thin material.

Henry's the best, except for the mysterious -- and strangely familiar -- assassin hot on his tail. Enter Will Smith version 2, a digitally de-aged twentysomething clone with the face of the Fresh Prince and the dynamism of Smith circa the first Bad Boys.

Now playing: Watch this: Gemini Man: A closer look at de-aged Will Smith

It shouldn't really mean anything that Gemini Man began life as a much-trumpeted script back in the 1990s, because no doubt very little of that original script survived the decades of development. But it really does feel like only the technology has been modernized, as the story and dialogue feel incredibly dated. In this day and age, a movie has no business spending as long as Gemini Man does on such a witlessly hackneyed setup. At least a half hour is wasted on bureaucrats in offices frowning at each other about "assets" and "loose ends," punctuated by drearily familiar action scenes like body-armored kill teams storming a hero's idyllic country retreat (and getting a surprise when he rolls out of bed straight into murder mode). It's like someone trying to recite a Bourne movie from memory.

The high frame rate gives everything a smoothness that highlights the effects -- there's no hiding the de-aged face behind motion blur -- but it gives everything a TV feel rather than the texture of cinema. The choice of locations also adds to the low-budget, vintage feel, with early scenes in sunny Georgia looking exactly like a '90s Jean-Claude Van Damme actioner. Or perhaps even the 1991 movie Double Impact, in which Van Damme played a dual role -- and he didn't need fancy CGI when he had a pot of hair gel.

It's hard to properly evaluate Gemini Man's de-aging effect fairly because you're looking so closely at it, but it genuinely doesn't feel weird or obviously fake. We'll probably only be able to tell how good the effect is in a few years by watching the movie again. The downside of that is you'd have to watch the movie again.

Enlarge Image Ben Rosenstein

To be fair, Gemini Man shines in its action scenes. You can really see what's going on in the entertaining fights and chases, many of which appear to be done in one take without confusing editing. During the assorted fistfights the camera gets right into strike range of the combatants, putting you slap bang into the midst of each brawl. On a vast Imax screen, the effect is very cool -- although the smooth frame rate, 3D and huge screen will probably cause a few headaches.

The problem is everything in between the action scenes. Gemini Man's technological innovation drowns in endless spy cliches, half-heartedly generic twists, forgettable dialogue and non-existent characterization.

If I had to single out one issue in particular, it's that even when playing a relentless government killer, Smith still has to be the good guy. A braver movie would have made one of the assassins an unredeemable monster, which would give some resonance to the idea of his younger self potentially taking a different path. It also would have been cool to see Smith cut loose playing a real villain. As it is, Old Will is so cuddly there's no stakes to Young Will following in his footsteps. If only the film had leaned into the goofy premise, it could have been the CG era's Face/Off instead of this era's Double Impact.

In the days when Netflix and Instagram and whatever else compete for your attention, it's at least commendable to see a movie that's so completely designed for the big screen. When Martin Scorsese unveils his own digital de-aging technology in The Irishman, most people will only be able to see it on the small screen when it's released on Netflix Nov. 27. So it's great to see a movie that goes out of its way to give you movie-sized entertainment.

But Gemini Man's man-vs-himself hook has been done so much better elsewhere. You'd be better off watching the brief fight between young Captain America and his older self in Avengers: Endgame. You could watch Tom Hardy give a dual acting masterclass in the otherwise forgettable Legend. Heck, even Looper did it better pitching Bruce Willis against Joseph Gordon-Levitt in a rubber nose.

There's an important lesson here: Cutting-edge effects have to serve a good story. Gemini Man is worth seeing on a big screen, but it won't be remembered as the cinematic milestone it could have been.

Originally published Oct. 4.