HUGELY high-tech and forward-thinking in its day, Tron now looks cheesy and quaint in retrospect, with its blocky graphics and simplistic blips and bleeps. The original film from 1982 was all about the possibility of technology and the human imagination, and the adventures that could result from marrying the two; but only now are the computer-generated effects available to render this digital world in its fullest potential.

Hence, nearly three decades later, we have the sequel Tron: Legacy, which is in 3-D (of course) but is actually best viewed in IMAX 3-D, if that option is available to you. The whole point of the story and the aesthetics are that they’re meant to convey an immersive experience. We’re supposed to feel just as trapped inside this challenging and dangerous electronic realm as the film’s characters.

And at over two hours, we are indeed trapped — there is no justifiable reason for such a lengthy running time, especially given that the original got in, did what it had to do and got out in about an hour and a half. While director Joseph Kosinski’s feature film debut is thrilling and cool-looking for about the first half, its races, games and visuals eventually grow repetitive, which only draws attention to how flimsy and preposterous the script is from Edward Kitsis and Adam Horowitz.

Tron: Legacy is a mishmash of pop culture references and movie rip-offs, Eastern philosophy and various religions, and one insanely cute, strategically placed Boston terrier. And with the return of Jeff Bridges in the lead role, there’s plenty of Dude-ishness for you fans of The Big Lebowski. (At one point he complains, “You’re messing with my Zen thing, man.”) It’s all giddy, ridiculous fun for a while, set to an ideally integrated techno score by the French duo Daft Punk. But a little of this goes a long way, and eventually you realise there’s not much there; no real point beyond exhilaration.

Bridges’ video game developer Kevin Flynn was aiming for deeper meaning, or at least a new level of consciousness, when he created the Grid all those years ago. Now, his estranged son, Sam (Garrett Hedlund), discovers that’s where Dad’s been all this time — sucked into the Grid and stuck there for the past two decades. The place Flynn built with high hopes is now dominated by the tyrannical and not even vaguely fascist dictator Clu (also Bridges, digitally tweaked to look like a 35-year-old version of himself), the doppelganger Flynn created to oversee the operation. Younger Bridges is uncanny and nearly seamless — until he opens his mouth, and then everything goes kinda wobbly. But for the most part, it’s a neat trick.

The confident and good-looking Sam similarly gets drawn into this parallel universe and quickly finds himself thrust into the middle of a sort of floating gladiator arena. Throngs illuminated in deep orange cheer ravenously as opponents try to shatter each other, literally, by hurling the discs that are attached to the backs of their neon-glowing bodysuits. Next up, Sam is forced to take part in the deadly lightcycle races — which look infinitely better here than in the original — and, being your typically rebellious, motorcycle-loving loner, he naturally fares rather well.

But this spectacle is as overwhelming for Sam as it is for us — even though Sam has the benefit of his dad’s DNA — and so he’s happy to accept help escaping from the mysterious Quorra (Olivia Wilde, bringing complex emotion to what could have been a beautiful but forgettable character). She has long served as Flynn’s protégé and does the honours of reuniting father and son; should they stay or should they go becomes their ultimate debate.

The moment Flynn and Sam first see each other isn’t filled with wistful emotion so much as confusion, and it takes place at Flynn’s distractingly stylish, glowing white-on-white lair. The place suggests what might have happened if the Dude had matured a bit and moved into a loft designed by Philippe Starck — although, unfortunately, there is no rug that really ties the room together.