I scored free passes to a sneak preview of Christopher Nolan’s hotly anticipated sci-fi/action opus Inception last night. And although I hadn’t been exposed to all that much of the hype, I had been tainted enough to go in hoping for a jaw-dropping spectacle.

What I got was a mess. An ambitiously constructed, sporadically clever mess, but a mess nonetheless. Inception is basically a cross between Ocean’s Eleven and Flatliners – a group of slick, attractive guys (and token girl) who perform elaborate heists in the dreamworlds of their victims. Tempted by the promise of one last score, involving the tricky process of “inception” – planting an idea in a subject’s head and making him think it was his – Dom Cobb (played a little too forcefully by Leonardo DiCaprio) assembles a crack team of subconscious bandits to make it happen. But a “projection” from his turbulent past does everything it can to sabotage the mission.

The concept is interesting enough, and sets the stage for some amazing sequences, where activity in the real world bends the laws of physics in the dream (a zero-gravity fight scene being the most memorable). But if you’re looking to go beyond the fantastical to elicit some kind of meaning – something the film practically demands with its oh-so-serious score and pseudo-religious lingo – get ready for a headache. Cobb’s backstory is intriguing at first, his questionable relationship with his now-deceased wife (Marion Cotilliard) giving some emotional resonance to all the high-octane action. But after what seems like dozens of scenes with DiCaprio and Cotilliard staring morosely at each other, this initial intrigue evaporates. And as the plot lines get progressively more complicated – boy meets girl in real life, then they get trapped in a dream world and live together there for 50 years, then they return to reality but aren’t sure if it’s really reality, then continue to see each other in dreams after one of them dies, or something like that – it becomes impossible to care.

Nolan must have thought this sort of heavy-handedness would provide the dramatic heft necessary to upgrade Inception from sci-fi popcorn flick to philosophical tour de force, but it only succeeds in dragging everything down, making an already bloated two-and-a-half hour run time feel like three.

Which is too bad, because there’s an awfully fun summer movie hiding beneath all the weepiness and high-minded ideas. The chase scenes are taut and imaginative, CGI sequences of exploding cafes and runaway freight trains are beautifully executed, and the supporting cast is pretty wonderful. Joseph Gordon-Levitt gives a masterfully reserved performance as Cobb’s sidekick Arthur, including a total charmer of a scene with sort-of love interest Ariadne (a workmanlike Ellen Page), and Tom Hardy is a godsend as Eames, the smarmy, sarcastic “Forger” (a guy that impersonates people in dreams).

But Inception is out to show you more than a good time, and becomes a murky metaphysical puzzle as a result. You’re gonna be better off exploring dream worlds of your own.