In desperate need of a laugh-till-I-cried, I went to see Bruno last night. Or rather Bruno with an umlaut, which quickly becomes the film’s knock knock joke (a hint I should have taken). Admittedly, reviews were somewhat mixed: it had earned four stars from the Financial Times whereas Time Out London awarded it a more modest three. Still, even critics who accused Sasha Baron Cohen of using the same cheap targets he’d skewered in Borat, promised a mix of belly laughs and horror at the film’s irreverence. The African baby Bruno christens ‘OJ’, the Hitler jokes. You know: ha ha.

What’s wrong with Bruno has nothing to do with shock, or even the fact that it tells jokes you’ve heard before. In fact, Bruno commits a far graver cinematic sin: it’s an utter bore.

First, it’s difficult to imagine any context in which more than an hour’s worth of jokes about penises, anal sex and dildos take on the status of high humour. And what’s perplexing is why critics who would undoubtedly sneer at puerile jokes about boobs and farting when they come out of the mouths of frat boys, pee their pants laughing when Baron Cohen straps one on. The difference is lost on me.

Second, Baron Cohen’s doctrinaire adherence to the notion that nothing is too outrageous to laugh at appears to blind him to the fact that some scenarios simply don’t lend themselves to his style of humour. For instance, take the scenes in Jerusalem where he aims to become a celebrity by brokering a peace deal. Flanked by sombre-looking Israeli and Palestinian officials, Baron Cohen’s feeble jokes fall totally flat. For their part, his guests are highly unamused because there’s nothing to laugh about, and we the audience know it.

This scene exposes the fact that Baron Cohen’s humour only works when it’s based on simple moral dualisms – taking the piss out of racists, homophobes and religious fanatics, for instance. In morally complex, highly charged situations it doesn’t work because it can’t  figure out who it’s really taking the piss out of, and Bruno’s ingenuous ignorance isn’t nearly canny enough to fill the gap.  (In fact, I’d say that only black humour works in scenarios like these; see work by the Palestinian filmmaker Elia Suleiman, for instance.)

Similarly, Bruno’s attempt to entrap Ron Paul, the failed candidate for the Republican presidential ticket, in a hotel room sex scandal comes across as unpleasant and mildly embarrassing for Bruno, but not Paul. And it’s obvious why: too little is known or remembered about Paul for him to loom as a villainous figure of fun so there’s no delight to be had in the prospect of seeing him fall, or even blush for that matter. Instead, he comes across as a hapless bystander who stumbled into Baron Cohen’s odd little movie.

Finally, there’s the fact that we’ve seen Bruno before. No, not from Baron Cohen, but from a funnier and subtler comic, Mike Myers. Anyone who remembers Dieter from the Saturday Night Live skit Sprockets, with its black turtlenecks and ‘Germany’s Most Disturbing Home Videos’ will no doubt see echoes in the Germanic Bruno. But Myers knew when the joke was funny precisely because it wasn’t, and his excruciating humour emanated from his willingness to push tension to the breaking point. The gag never felt cheap and he never announced a punchline, because he was the punchline.

I’m still convinced that Baron Cohen is a genuine talent, and there’s something admirable about his ‘anything for a gag’ humour. The trouble is that ‘anything’ is starting to feel like the same old thing, the beginnings of a creative rut.