Snowpiercer has ideas -- a lot of them. Were we not all living in an age where the movie industry's biggest powers are either out of fresh inspiration or simply uninterested in ginning some up, I might be inclined to say it has a few too many. But we do. And so, I won't. All those ideas are wrapped up in a train that has too many cars to count and serves as both a sanctuary and prison to all of its inhabitants.

The Snowpiercer hosts what remains of humanity after an ill-fated attempt to curb the effects of global warming plunged the world in to a deadly deep freeze. It chugs around the world at high speed -- smashing through ice buildups along the tracks -- pitting its passengers against each other. Close quarters and the near-extinction of the human race have a way of ratcheting up tensions. Who knew?

At the rear of the train are the "freeloaders," as Tilda Swinton's bucktoothed stooge character Mason calls them at one point. Led by Curtis (Chris Evans), Edgar (Jamie Bell) and their mentor, the multiple amputee Gilliam (John Hurt), they live in squalid conditions. They are routinely bullied by the comically cruel Mason, who works at the behest of Wilford, the mysterious Oz-like figure situated at the very front of the train who is the architect of a sort of locomotive purgatory.

Moving back to front -- in between the have nots and the have -- is a progressively better existence. At the back, you eat globs of protein and are subject to indiscriminate rifle butts to the face. Closer the front, thanks to Wilford's self-sustaining masterwork of a train, you can go to the spa or eat sushi (only twice a year) or take designer drugs at a rave. No surprise, then, that Curtis and company eventually summon the courage (or tap in to their shared desperation) to try and hijack the train car.

Each car represents a new ecosystem for Korean director and writer Bong Joon-Ho. From the misty orange sauna to the turquoise aquarium car to the pastel, gonzo schoolroom, Joon-Ho takes full advantage of these wildly disparate settings to tell a story about a train to hell as a whole. All around them is the sprawling, intimidating whiteness of the unforgiving Earth. You're truly getting every color of the rainbow here.

He introduces a lot of characters -- from the drug-addicted father-daughter duo Namgoong (Song Kang-Ho) and Yona (Ko Ah-Sung) facilitating Curtis' bum rush to the Wilford-addled teacher played by Allison Pill to the frantic mother Tanya (Olivia Spencer). And yet few of them seem superfluous. You can't understand the sheer despair of the passengers in the back without the likes of Tanya. And you can't understand the cult-figure status of Wilford without Pill. Without Namgoong and Yona, there is no bridge -- literally or figuratively -- between the two sections. Nor are there any of the terrific action sequences that come with claustrophobic hand-to-hand combat of a mutiny segmented by secured doors.

That's not to say that there isn't a bit of baby fat to this picture. Wrangling over the final cut of the film aside, it does feel like certain parts could be leaner. There's also a decided lack of polish, both with the special effects (the Hoth-like landscape wasn't as bleak and intimidating as it could have been) and the dialogue, that shines through at certain unfortunate moments.

But on many a level it feels wrong to ding a film that has an abundance of ideas -- that has dizzying action sequences alongside the humor of Tilda Swinton pulling out a set of false teeth -- when such qualities are so sorely lacking in so many other cinematic corners.

This is a clever allegory that defies specific political persuasions. It acknowledges the threats of global warming and the growing inequality, but falls well short of suggesting that there is an easy or obvious solution for either. It even dares to suggest that we might make things worse before they get better. There's an almost stunning level of sympathy for Wilford even as you pull for Curtis to make his way to the front of the train.

There is plenty to unpack -- to go home and think about -- which all by itself makes Snowpiercer worthy of some level of celebration.