CONTAINS BIG SPOILERS
Well, it's big. Forget what Douglas Adams said about space, this is bigger than the biggest thing ever and then some. The apocalypse is here, pretty much, and fortunately there's a sense of humour and a sense of humanity on show to make the last days of homo sapiens bearable. Whereas the impending extinction of human life in Man Of Steel was tiresome and dull, for all the spectacle, and the relentless trashing of cities raised not a flicker of interest in the Transformers saga, Guillermo Del Toro manages to balance the eye-searing visuals with a sense of the tiny individual human beings, the men and women at the centre. You never got a sense of the people in Battleship or Transformers as people: they've given no colour, no backstory, no humanity, and the cast and director aren't able to provide them with any depth, so there's nothing to connect to emotionally when things start blowing up. The characters of Pacific Rim aren't hugely layered, it's true, but enough is sketched in to make them, if not fully rounded human beings, then at least reasonable facsimiles of same rather than cardboard cutouts with the depth of the promotional standees in the cinema foyer.
Massive gribbley monsters, dubbed Kaiju, start erupting out of a dimensional breach at the bottom of the sea, and start stomping on the coastal cities. The only hope is to create monsters of our own: equally outsized robots controlled by two pilots within the skull. In order to fully control these metal behemoths, the pilots have to "drift": merge their minds so they think and act as one. But the Kaiju are coming through faster and bigger and smarter and the Jaeger Programme is about to be shut down in favour of a giant reinforced wall to keep them out....Will the last few pilots and the surviving battledroids be enough to seal the rift and take the planet back?
The visual effects are absolutely stunning and there's not a single pixel out of place. Better, they do convey the sense of a physical object rather than the digital file pasted in afterwards: you'll believe that's a 250-foot robot and not just a drawing in Microsoft Paintbox. (Compare with Man Of Steel which, for all the gosh-wow spectacle, never suggested there was any physical reality to the effects.) Bravely, considering the light-loss issue with 3D, all the monster/robot fighting takes place at night, in (or under) water, frequently in heavy rain, which frankly makes the CGI work that much more impressive than if they'd slugged it out in broad daylight. Both monsters and robots are well designed, and the battle setpieces are well enough shot that you can actually see what's happening most of the time, unlike the huge robot fights in the Transformers series.
Perhaps the constant comparisons to other movies isn't entirely necessary or illuminating, but it needs to be pointed out where Pacific Rim gets it so right and Man Of Steel, Battleship and the Transformers series didn't. The trump card is a sense of humour, from the knowingly absurd names (in a year's time you won't be able to move in a maternity ward for baby boys called Stacker and Pentecost and Raleigh) to the hilarious double act of wacky scientists who frankly deserve their own franchise. Del Toro regular Ron Perlman contributes an enjoyably larger-than-life cameo as well (and stay to the end of the main credits for a nice payoff). And that comedy leavens the destruction which, again, gets a little wearing after a while. Humourless spectaculars like Man Of Steel and Transformers 3 have somehow made toppling skyscrapers worryingly dull, but for the most part Pacific Rim holds the interest amidst the chaos.
So the bottom line is that I really enjoyed it. I saw it in 2D (and ensured the cinema hadn't left the filter on like they did for two films last week) and it probably doesn't need the extra dimension, working perfectly well flat. Oddly for a modern spectacular, it's been made in the 1.78 ratio rather than the wide 2.35 - like Spielberg's War Of The Worlds, this allows the vertical height of the monsters to be emphasised without losing them in the horizontal width. The 12A is probably the right certificate as well: the action sequences are probably too intense for the kiddies, and there's one use of the dreaded F-word (which I didn't catch over the sound of roaring monsters and clanking metal and things smashing into each other).
Certainly it's not Guillermo Del Toro's best film - it's no Pan's Labyrinth - and it has little of the dark magic or sweet charm that you'll find in his smaller, more personal films. But if you are going to have vast summer blockbusters aimed at 13-year-old boys in which robots and aliens punch each other in the face and club one another round the head with cargo ships, better this than yet another damnable Transformers. It's a lot of fun, excellently done with nuggets of unexpected pleasure (like the tantalising glimpses of the Kaiju dimension), and well worth seeing. I might even go again and see it in shakychair D-Box.