(Dir. Garth Jennings 2005)

I must first state my bias. I listened to the Hitch Hiker's Guide to the Galaxy when it first came out on radio, and almost immediately became a fan. I could recite almost the entire second series, and large chunks of the first. I used to do this for my school friends in the playground, and it amazes me now that they actually stood about to listen. Many people now mistakenly refer to the book as the original. It was not. The project was originally conceived as a radio series. Many of the ideas in it were specifically tailored to a radio audience, such as one character's having two heads. Because it was radio, the writer could put such things in, knowing that they would cause no difficulty. He similarly added such things as vast tracts of hyper-space within planets, large enough to build other planets in, and a hundred exotic aliens that needed just a few squelching noises to conjure up. On radio, the pictures are so much better.

The radio series were rather uncomfortably translated into books, then a rather low-budget BBC television series. For many years, Hollywood executives tried to get a film version of the project made, but Douglas Adams stoutly resisted all attempts made by those executives to ruin his creation by changing everything. They wanted to recast with American actors, change the setting to America, and then change everything else while they were at it. And so the film version remained absent, until Douglas Adams died dishearteningly young. Suspiciously soon after this sad event (Douglas was by all accounts a thoroughly excellent chap), the film project got off the ground.

I'm happy to report that some sort of compromise was reached, and that not all the cast of the film is American, and not everything has been changed. Instead, half the cast is American, and just enough of the script has been changed to render the film mediocre, rather than appalling.

In the radio series, Zaphod Beeblebrox is cool, but in the film he is just an idiot. In the original, Ford Prefect passes as an Englishman, who clearly and for the most part calmly explains things to Arthur Dent. In the film, he is an almost unintelligible American with a towel fixation, who adds very little. In the original, Trillian is an intelligent Englishwoman with degrees in mathematics and astrophysics. In the film, she is an American girl who looks just about old enough to leave school.

Now, of course it would be silly to imagine that every last detail of the original would survive in the film version. For a start, the first series alone lasted three hours, and was packed with action and dialogue, so some pruning would be inevitable. However, the pruning seems to have been done by a committee of morons.

All the way through, there are narrations by the Voice of the Book. Douglas Adams was a bit of a whiz with language, and he spent many hours or even days agonising over individual words, and eventually constructed some of the finest sentences in the English language. His playfulness with grammar and his exotic vocabulary made his phrases memorable and entertaining. Alas, the producers of the film seem to think that the attention span of a modern audience would not last to the end of Douglas's more ambitious sentences, and that any word longer than "sponge" or rarer than "the" should be included with caution. In short, the language is dumbed-down. Thus is one of the work's greatest strengths lost.

The Hitch-Hiker's Guide to the Galaxy has a devoted fan-base. Pleasing this sector of the audience would clearly be a must, and so changes to the original would have to be made only when utterly necessary and when the results were indisputably better. There are many great ideas and running gags in the original series. One is that Arthur Dent, despite much trying, never ever gets a cup of tea. In the film he gets one. Another is that galactic hitch-hikers carry towels because they are the most massively useful things that they can carry, and that they are a symbol of a hitcher's prowess. The towel idea is never explained in the film, and anyone unfamiliar with the original would never guess why they are so significant in the film, and miss out on a clever idea. Instead, all he would see is a bit of confusing silliness.

Change for the sake of change is annoying to the fans, and makes no difference to the uninitiated. Why then, I wonder, is the original deep booming voice of the super-computer Deep Thought changed to a matter-of-fact woman's one?

The original script was studded with first-class gags. Many of them were quick. At the risk of being sued for copyright infringement, I shall quote just one:

ARTHUR: You know, it's at times like this, when I'm trapped in a Vogon air-lock with a man from Betelgeuse, and about to die of asphyxiation in deep space, that I really wish I'd listened to what my mother told me when I was young.

FORD: Why? What did she tell you?

ARTHUR: I don't know, I didn't listen!

It is therefore both annoying and positively perplexing that such gags are missed out. That they would have added to screen time is no explanation, because instead what we see is usually a pause in the place of the gag, and quite often a lot of other time-consuming things have been added in.

Douglas was excellent at constructing spectacular and funny anti-climaxes. The makers of this film were not. When Arthur first wakes up to find himself off the Earth in an alien space ship, on the radio we hear him informed of where he is, that he has just been through a matter transference beam, and that he is now surrounded by aliens. In the mind of the listener, there might be an image of alien sophistication, of gleaming instrument panels and high-tech wonder. When asked what he thinks, he replies "It's a bit squalid, isn't it?" - a wonderful anti-climax. Instead, in the film, we see the squalid surroundings straight away, and so this is thrown away. This didn't have to be. We could have seen close ups of Arthur's face, had the background largely in darkness, and seen Ford through the blurry haze of Arthur's transference-beamed eyes. Then, as the picture settled down, we could have returned to a shot of Arthur's face, Arthur could have said his reply, and then we could have seen the squalid surroundings properly. Another moment lost. There were several others, not least Deep Thought's announcement of the answer to the Ultimate Question.

The makers of the film seem to have managed to miss what all the strengths of the original were, and instead concentrated on other things. The original plot was great, in the way it tied everything together. The film's plot is quite different, and doesn't really resolve or explain anything. Instead, we have a rather disappointing and conventional love story between Arthur and Trillian added, and the explanation of everything seems to be just "Love conquers all". The language, the characters, the world setting, the scientific ideas, the philosophical ideas, are all lost or diminished. Even most of the really good gags are missing.

Another example of how the film makers missed the point: it turns out that the Earth was manufactured, and that a company is making a replacement. We see some workmen painting Ayer's Rock red, so that it looks like those photographs of the rock taken at sunset. On its own, this is perhaps a cute little gag, but in the context of the film it is positively destructive. It is silly to imagine that entire planets would be made by workmen hand-crafting each little piece, and if the rocks of the Earth were really just painted to look the colours they are, then we would have discovered this thousands of years ago, and not been fooled into thinking our planet a natural thing. Also, sunset is not a permanent state of affairs. In other words, the joke bursts the bubble of the story's setting. Douglas's ideas were humorous, but for the story to work, then the audience has to be able to accept that they might at least be possible.

So is the film void of virtue? No. The special effects are mostly good, and some shots create a great sense of scale. The Vogon ships are huge, square and ugly and rush around in much the same way that bricks don't. The Vogons have great faces. The space-ship Heart of Gold zaps about the galaxy in an amusing manner. Though the humour is sadly diluted, expurgated, and made simpler and more ordinary, it is still better than most film humour, largely because the original was so good that even a large amount of misguided tinkering could not destroy it utterly. Some of the performances are decent. Martin Freeman was an interesting choice for Arthur, and perhaps with the right direction could have been very good indeed. He ended up playing Arthur as a bit angry and as a perhaps credible lover of Trillian, whereas Arthur really works better as an indignant representative of a type of human rather than as a put-upon individual.

The original Hitch-Hiker's Guide to the Galaxy is available on BBC compact disc audio recording. Get that. It's great.