What most of us remember about this film is the sheer and utter scope. The teaser (showing an explosion the size of skyscrapers billowing through New York flinging cars aside like toys) raised hairs on the back of the necks of cinemagoers everywhere. Even until his self-confessed 'last global disaster movie', 2012, few directors dared to dream as physically big as Roland Emmerich.

And everything about this movie was big, from the spaceships that attack Earth to the destruction their weapons wrought. Scenes of Washington, New York and Los Angeles being swept clean by fire are etched in all our memories for a good reason no matter how hammy the drama, dialogue or characterisations were. It wasn't the start of special effects movies, but it was the start of the money shot in special effects movies. Not even Star Wars had a single shot that encapsulates everything it was about like the White House erupting under the alien ship's giant gun.

And don't forget the dog. Yes, it also wouldn't be a Roland Emmerich movie without the kind of ropey all-American touches that hold his films far back from greatness despite the audacity of his creative/destructive vision.

Tailor made for the treatment he'd become famous for, it's the story of an alien invasion. As writer/producer Dean Devlin says on the DVD extras, the invading creatures are the new tenants and humanity is the cockroaches.

Bringing together a fighter pilot (Smith in the role that made him a star), the US president (Pullman at the popular pinnacle of his career) and the science nerd who works the whole thing out (Goldblum), Devlin and Emmerich construct a cadre of disposable characters to speak the mostly primary-school dialogue and deliver the increasingly silly exposition (planting a virus in an alien operating system??)

But none of that matters. What mattered was the anticipation of seeing bigger things on a movie screen than we'd ever seen before. It's easy to remember this as one of the big arrivals of the CGI era, but in actual fact most of the effects were in camera. Shots of the crafts' smoky arrivals were achieved by squirting ink into water tanks, and fire billowing through city streets was done by turning miniature cityscape models up on their sides and lighting fires at the bottom.

It gets claggier on every repeat viewing, but this is first-look stuff all the way, bluster on a global scale to hide the plot holes and disguise the hackneyed characters. It was just in time to catch the derision of all things huge in Hollywood that's still in vogue now, but the formula's been working for Emmerich ever since.