That was brilliant! However this is a very specific kind of brilliance, with stupid superhero costumes that would have looked unrealistic in 1960s Doctor Who and boy band lead actors wearing more make-up than Cleopatra.

Firstly, some background. Do you know what a Japanese tokusatsu show is? "Tokusatsu" means "special effects" and it generally involves the kind of Godzilla-inspired extremes of rubber-suited realism that can bring grown men to tears of laughter. Do a Google image search for Ultraman's enemies. Alternatively, imagine a 1960s Jack Kirby comic book put exactly on screen with no concessions whatsoever to the live-action medium. In the West, this would be a parody... but in Japan, it's not. They're taking it seriously, which is what makes it even funnier. The original version of Power Rangers didn't have those silly comedy inserts, you know.

So I'm sitting at the front of a Japanese movie theatre, expecting kids' nonsense, when suddenly I find myself watching six-foot-tall free gifts from a cereal packet using martial arts on each other. All being done seriously, with a story and everything. This is the greatest form of entertainment to be found in a cinema.

Then you've got the cast. Obviously the target audience is five years old, but infants can't buy cinema tickets. Thus they're trying to draw in the mums too, by filling the cast with pretty J-boys with jewellery, make-up and/or dyed blonde hair with ribbons in it. Hilarious. It's unspoofable. The worst of them you'd swear was a drag queen. However there's also something for the dads in the audience, in the form of a sexy train stewardess in rubber.

It's an unusual kind of superhero movie, though. Normally, these films are about their heroes. You know. Spider-Man is about Spider-Man, and so on. However there are two ways in which this film isn't just about Kamen Rider. Firstly, this is the franchise's 40th anniversary, so although it stars the heroes of the latest (21st) TV series, it's also a time-travel adventure about the original Kamen Riders from 1971 and the all-action finale brings together about sixty or seventy different Kamen Riders from all the eras in between to beat Galactus. (Well, sort of.) They all fly into the air on their motorcycles in a "40" formation, which is the point where I guessed this might be some kind of anniversary celebration.

The film's other structural peculiarity is the way half of the leads are small children. Furthermore, this works. You'd expect them to be annoying, but they're not. On the contrary, one of those small boys is giving the only proper performance in the movie and I'd bet money on him having a long and successful future in the business. His name's Imai Yuki and he's playing Misuru. He cries well and he has two important scenes, both of which he gets right. (Admittedly there's also that lugubrious dude who played Satan's Toenail in the 2004 Kekko Kamen films, but he's coasting on screen presence and a deep voice. Mind you, I think it's him who gives a "let's go" straight to camera.)

Anyway, the children are really important. They get all the meaty emotional material. They're the ones from the altered 1971 timeline in which Shocker took over the world. They keep being the most important people in the movie, when the Kamen Riders get their arses kicked by the bad guys. (Unpredictability is good.) There's a slow bit at the end of the film when the kids get written out and it's just twenty minutes of non-stop Kamen Rider action, which is admittedly what the target audience wants to see but is still fundamentally just a big action sequence and inherently less interesting than the children. Fortunately though, Imai Yuki gets a big scene afterwards which for me saved the last act. Seriously, when it comes to the children this is a solid SF film with more plot complexity than you'd expect and some genuinely good bits. I'm not saying that ironically, either.

However that said, those last twenty minutes go from "huge" to "mad" to "completely out of your tree". Remember all those complaints about Galactus being a big tornado in Fantastic 4: Rise of the Silver Surfer? This is how that film should have been. This ends with Galactus, but Japanese and with the trademarks filed off. Whoah.

So in other words, this works both as a straight film and as a celebration of rubber-costumed absurdity. The balancing act with the latter is, I submit, brilliant. No one ever lets on that there's anything silly at all in what they're doing... but you've got the Ninja Who Say Hee. You've got a fight scene through which a rubber bird-man is swinging on a kirby wire, as if he's a pendulum. You've got Squid Man. You've got men who transform into equipment, including the "you have got to be kidding me" talking sword. You've got gloriously cheap CGI and camera-shakes every time someone blasts a fireball. You've got a turtle-man with a cannon on his back, who's silly-looking even compared with the rest of the film.

Their 1971 doesn't look like the 1970s, though. No matter which era we're supposedly visiting, it all looks like 2011.

I loved all that. Seeing it in a cinema was to know magnificence. However at the same time, it's not negligible as a proper film either. I liked the children discovering that they'd been cruel or unfair to people who were actually heroes, including other children like the little girls on bicycles. I like the way they set up the stealing. I like the unexpected emphasis on ordinary people in a superhero film. Seriously, I was impressed.