Don't panic - The Hitchhiker's Guide to the Galaxy is not as bad as I had feared. Then again, it is not as good as I had hoped.
Stuck in development hell for the best part of 26 years, Douglas Adams' book has finally reached the big screen - four years after the author's death.
Adams' deceptively complex novels are crammed full of witty erudition, great gags and lengthy digressions, so it was always going to be a struggle to turn it into a neatly packaged two-hour movie.
Understandably perhaps, huge swathes of the novel have been cut in order to make a consistent, story-led film.
At the same time, director Garth Jennings tries hard to retain the comedic essence that so defined Adams' originals.
Beguiling
The Hitchhiker's Guide to the Galaxy centres on the hapless Arthur Dent, who awakes one morning to find his best friend is an alien, his planet is about to be destroyed and that he is somehow central to a galactic scientific experiment to determine the meaning of life itself.
What marked the book out as more than a mere comedic romp was the density of ideas that Adams managed to distil in the text - everything from handheld computing to existentialism to musings on cricket and maths.
Sam Rockwell does a great turn as Zaphod Beeblebrox, the two-headed president of the galaxy; Mos Def is passable as Ford Prefect; while Zooey Deschanel is beguiling as Trillian.
As the voice of Marvin the Paranoid Android, Alan Rickman perfectly conveys the character's world-weary disdain, despite being woefully underused.
A lot of effort has gone in to keeping the film as faithful to Adams' vision as possible. But somewhere in the production process the crew has lost sight of the fundamental aspect of the books - they were immensely funny.
Truncated
The film burbles along at an amusing canter, occasionally rising to levels worthy of a chuckle. But unlike the books and radio series, it rarely makes you laugh out loud.
Some of the original gags find their way into the film version, but they feel neutered or truncated.
Screenwriter Karey Kirkpatrick, who continued the adaptation work started by Adams, has had to make a number of sacrifices to get the text into cinematic form.
Unfortunately, one of the elements sacrificed is sense.
Hitchhiker fans will know what is happening, but newcomers will be left scratching their heads at a story that flits from one unpronounceable planet to another - each one populated by equally exotic-sounding characters.
Did I say characters? Hmmm. While Dent is a familiar cipher, audiences will be left clueless by Ford Prefect, bemused by Zaphod Beeblebrox and indifferent to Trillian.
Despite outstanding production design and some fantastic visual effects, overall the film is a bit of a mess. A charming mess, maybe, but a mess all the same.
Did the script veer too far away from the source material or tie itself in knots trying to keep faith with it?
Bizarrely, I think the answer is both.
The Hitchhiker's Guide to the Galaxy is out in the UK on 28 April.