Can I say The Dark Knight is, in my opinion, not a very good film' I am puzzled and perturbed by the overwhelmingly positive critical response the film has attracted from fellow critics, especially in the US.

Let me list my main objections to Christopher Nolan's latest 'masterpiece'.

First, it is a mistake to assume the script (which the director and his brother Jonathan worked up from a first draft by Batman Begins writer David Goyer) is particularly original.

The Batman movie franchise is based on a comic-strip superhero who first appeared in 1939 with his ethical ambiguity firmly in place. Bruce Wayne is a rich, handsome industrialist who took revenge for the senseless killing of his parents by turning into a caped vigilante who enjoys killing and maiming villains (most of them social inferiors whose foreignness is sublimated in a series of outlandish physical deformations).

He has since been reinvented, and darkened, more than once - most notably by comic-book guru Frank Miller. This is relevant simply because film critics do not always read comics, and some reviewers appear unaware that every nook of the much-heralded 'moral complexity' and 'dark poetry' of Nolan's second Batman outing has already been explored, repeatedly, in comic-book form.

Secondly, sorry, but what moral complexity' The fact a weary Bruce Wayne wants to stop being Batman' The fact the Caped Crusader's popularity ratings are dropping' The fact Batman/Wayne wants to hurt bad guys' (What is he supposed to be, a flying Gandhi') The fact a maniacal, amoral genius forces our hero to realise some ethical dilemmas are just plain tough to solve' The numerous gratuitous parallels between Gotham's war on anarchy and the US's war on terror'

All of these are standard comic-book tropes. To dwell on just one: the transformation of upright, airbrushed attorney Harvey Dent into deformed, cynical vigilante Two Face is not remotely credible. The moment he turns towards the camera to reveal his grotesque face (the result of an accident so casually managed it looks like a YouTube parody) was the moment the film pushed me into outright hostility. If you want moral complexity, go watch The Lives Of Others.

Third, the 'thrilling' action sequences. The opening heist scene, with its enjoyable cross-double-cross structure, is well played, but some of the later action scenes - especially the climactic tussle - are boringly and confusingly edited, winging it on special effects rather than timing and also lacking in suspense. And the cutting between ticking-bomb-laden ferries is as lame as the same scene's insultingly casual set-up.

Finally, the performances. Christian Bale is all right, though his Bruce Wayne is lacking in charisma and it is hard to understand why his two helpers (Morgan Freeman and Michael Caine, both wasted) are so devoted to him. And Maggie Gyllenhaal struggles gamely with a demeaning role - a career woman who behaves like a secretary (though not, alas, like the one she played so brilliantly in Secretary).

Which leaves Heath Ledger as the Joker. Yes, he's good. Yes, the tragedy of his death casts a shadow that is difficult to separate from his performance. But his Joker is memorable for the wrong reasons. It's a self-contained island within the film.

There's a disjunct between the way the character is written - as a twisted monster interested only in creating moral and social mayhem - and the way he is played - as a weary existentialist.

It adds to the performance, but takes away from the conflict, and it left me unconvinced there is actually anything evil about this Joker. Watch Javier Bardem's Anton Chigurh in No Country For Old Men and you don't want to meet the actor in a lift. Ledger's Joker, on the other hand, looks as if he's bored with his fiendish enterprise and is about to go off to start an organic farm.

Sure, The Dark Knight is pop entertainment. Paint it black by all means, but don't pretend it's Hamlet.