Ludicrous vanity project, boundary-pushing experiment in the cinematic form or merely a triumph of style over content? It's been called all of those. Personally I couldn't call it an unqualified success, but I liked it.

It's Zack Snyder's first original movie, after the Dawn of the Dead remake, 300, Watchmen and Legend of the Guardians: The Owls of Ga'Hoole. He's doing Superman next, with Man of Steel. That's a lot of remakes and adaptations, which makes it interesting that this movie is at once violently, madly original (to a fault) and yet also a giant homage to everything.

Think of anything that looks cool. It's in here. 1. Luscious 1930s period setting? 2. Hot women with guns? 3. Computer games as a theme, visual motif and model for the "fantasy within a fantasy" sequences? 4. Fight scenes with thirty-foot tall samurai monsters that could take on Godzilla? 5. Orcs and dragons? Yup, all those. 6. Steampunk zombie Nazis? Okay, that's a stretch because I think these German soldiers are from WW1 rather than WW2, but what the hell. 7. Star Wars? Believe it or not, that's very nearly another "yup". The serial numbers have been filed off, but to see Emily Browning carving up robots with her katana in a very prequel trilogy setting is to be reminded as never before of the samurai roots of George Lucas's Jedi.

It's certainly not an empty film, despite the impression it's sometimes given. That would be partly a side-effect of the video game theme. However its visuals are clearly all-important and here's a quote from one of the concept artists, Alex Pardee.

"A lot of the worlds that were created for Sucker Punch are an amalgamation of what Zack and us artists involved all thought were cool as kids: GI Joe vs Cobra, Kurosawa, Dungeons & Dragons, Frazetta paintings, robots, steampunk, Jessica Rabbit, Isaac Asimov's "Foundation" & "Nightfall" dealing with characters trying to escape an inevitable oncoming darkness, The Goonies needing to find enough jewels to escape their "evil suburban landlords", Lone Wolf & Cub, Final Fantasy, and so many other cool experiences that we all shared as kids who loved imagination and imaginary worlds. But given all of those influences, as I said before, there was no set rule. It really was 'take inspiration from these and do something original with it. Something cool. We'll start from there.' And from that point on it was a true collaboration to fit what was in Zack's head, but also push those boundaries past the norm and past what might have been expected."

That's why you've got things like a 25-foot-tall bunny-faced flying mech-suit turning up in a steampunk zombie WW1. This is an outrageous fetish movie of beautiful women fulfilling geek fantasies... but with no sex or nudity. It's a story about female empowerment, in a brutal movie where the plot's all about the worst kind of female exploitation and the aesthetic would appear to be more of the same.

I like that.

The story is mental. Imagine Inception (or, if you must, The Matrix), but filtered through the above aesthetic. Snyder has called it "Alice in Wonderland with machine guns", which as a one-line summary I don't think I can improve on. There's the Outer Reality (my terminology), in which Emily Browning gets sent to an asylum to be lobotomised, not because she's insane in the slightest but merely in order to stop her talking about what she's seen. One of the orderlies (Oscar Isaac) says he'll forge the doctor's signature and make it happen. "I've done it a dozen times." This is in the 1960s.

The Inner Reality though is set in the 1930s, with gangsters. Browning's now the new girl in a brothel. You might be wondering how we've jumped here, but that's a question that the film chooses not to answer immediately. What we do know though is that they're linked. Either might be the "real reality", with each containing a legitimate in-story reason for one to be a hallucination or fantasy world within the other, which means I think reviewers who don't perceive any ambiguity here are missing something crucial. (As the finale shows, they're also wrong.) Anyway, the inner and outer realities share cast, plot points and a similar five-day deadline until something terrible. In Browning's mind, they're bleeding into each other.

Then we have the Inner Inner Realities, which is where Synder goes apeshit. Here's the outrageous stuff. To criticise these bits for looking like video games is to miss the point that they're consciously addressing them, as is shown in voice-over dialogue. "Who sends monsters to kill us, and at the same time sings that we will never die? Who teaches us what's real and how to laugh at lies? Who decides why we live and what we'll die to defend? Who chains us? And who holds the key that can set us free... It's you." These sequences are basically empty action for its own sake, but they're still a triumph of mad filmmaking and I'd say they still have more weight, adrenalin and fun factor than similar epic action sequences I could point at in, say, the Star Wars prequels or the Matrix sequels. I liked them.

Admittedly they're not "real", but we could say similar things about all the realities here and they certainly have plot and character links just as strong with the Inner Reality as that does with the Outer. They still matter, both on a story level and a thematic one. After all, this is a movie about discovering freedom through fantasy.

Then there's Scott Glenn's character. I don't know who he is, but "God" seems as good as guess as any. I thought he'd dropped a clanger with his first delivery of "oh, by the way", but in fact he was merely making sure we noticed the line. He's an actor with a long and good-looking CV, incidentally, and you might recognise him as Jack Crawford in The Silence of the Lambs.

I liked what the film's talking about. I think it's doing new things with overlapping realities, which worked for me despite normally being a story-killing plot device as far as I'm concerned. Alternate universes, spit. There's an impending lobotomy! I'd have had trouble believing that one story point could have enough weight to support half a dozen universes and three layers of mutually incompatible overlapping realities, but that's because I hadn't thought of an innocent girl being lobotomised for the convenience and financial advantage of two men.

However at the same time, you'd have to be blind or wilful to shut your eyes to the film's aesthetic. The songs are as important as those in Moulin Rouge and they turn the film into a music video just as often as it becomes a game. Furthermore apparently Pink Floyd's "Dark Side of the Moon" works as an alternative soundtrack to the movie, underlining the themes and providing sound cues for action and inner monologues. What boggles me is trying to imagine how someone discovered that in the first place. Meanwhile the women are beautiful and the fetishes are pumped up to eleven, yet sanity has not left the building.

As for the acting, the supporting cast are all strong. Oscar Isaac fights heroically with the production design and wins. Carla Gugino returns from Watchmen. The actresses playing the main girls include pop stars, but they're not letting the side down as far as acting is concerned and they're convincing in the action scenes since Snyder had them training for all that like lunatics. Emily Browning has a blankness about her that in any other film you'd call woodenness, but here is clearly integral to her character. It's speaking of what's been done to her by men and how she's going to choose to fight back. For the first twenty minutes, she doesn't even speak.

Someone says "it's showtime", but here it's (nearly) forgivable because it's referring to an actual show. Stage, audience, costumes, etc.

This is a movie that's doing subtle things via outrageous kitsch. It's horrible, sinister and even shocking in what's going to happen to our heroines, yet it's also fun. It's serving up the kind of insanity that will have your brain spring a leak and, for instance, start criticising the 30-foot samurai Godzilla monster who's carrying a rocket launcher and minigun on the grounds that samurai disapproved of Western guns and regarded those who used them as cowards. Mmm, yes. Closer examination might have revealed that realism is taking a back seat. (I was also briefly disappointed that Scott Glenn wasn't Japanese.) This film didn't work for a lot of people, but it also didn't lose money and I'm in love with the way it's going out on the very furthest limb it can find and then machine-gunning it off, laughing. If you don't like the modern tendency towards safe studio films, here's a counter-example.

I might even hunt down the 128-minute director's cut, which puts back everything Snyder had to take out to get a PG-13. He had to submit it five times.