“Don’t Panic” in large, friendly letters should be written on every ticket sold to this, the big screen version of the play of the TV series of the radio play of the book that Douglas Adams wrote. And, in much smaller letters on the back of the ticket, it should say “mostly harmless”.

Old fans of the Guide shouldn’t panic, as the producers of the film version have gone to great lengths to stay faithful to the source material – though not directly. New comers should also not panic, as the story and humour are simple enough for anyone to pick up. The reason both should then take to heart “mostly harmless” is because the the film, while in the Douglasian-style, is not the Hitchhiker’s Guide to the Galaxy – but is fun nonetheless.

Martin Freeman, of The Office, is Arthur Dent – British everyman, who sits down to breakfast one morning only to then have to rush off and lie down in front of a bulldozer, to stop his house being demolished to make way for a bypass. In comes his friend, Ford Prefect (Mos Def) who has something very important to relate to Arthur that can only be divulged in the local pub.

Ford is, in fact, an alien. And he’s just discovered that Earth is about to be destroyed, to make way for a hyperspace bypass. As Arthur saved his life when he first came to Earth (a neat little flashback), Ford is about to return the favour – by taking Arthur with him as he “hitches a ride” off the doomed rock called Earth and onto the nearest Vogon spaceship.

In addition to our protagonist Dent and his companion Prefect, a galaxy of stars has been assembled to assist. Zooey Deschanel provides the aforementioned love story as Trillian, the last surviving human female. Sadly her role is pared back from her astrophysicist beginnings in the book and series to being mainly the “damsel in distress” and to being caught in a love triangle between Dent and Zaphod Beeblebrox, the three-armed, two-headed, gigantic-egoed President of the Galaxy.

Sam Rockwell as Beeblebox is a delight. He’s shallow, offensive and egotistical – in other words, just right as the man who would kidnap himself and steal the newest, fastest ship in the galaxy.

The very Britishness of the film is enhanced by bit players. Steven Fry is the voice of the book, and spins the role with just the right amount of intelligence and irony. Alan Rickman is the voice of Marvin, the Paranoid Android, and while Warwick Davis often seems to misjudge Marvin’s pathetic body language, Rickman’s droll complaining is pitch perfect. Bill Nighy’s Slartibartfast couldn’t be better cast, as is world weariness is, essentially, Nighy being himself.

Douglas Adams once complained that making his highly successful book/radioplay/miniseries into a film was like “trying to grill a steak by having a succession of people coming into the room and breathing on it.” After twenty years and just such a succession of people, Adams passed away before he could see the project come to fruition.

Would he have been happy? We will never know. The film adds a romantic subplot (that admittedly was barely brushed against in the original versions), cuts bits out that some may define as Very Important Parts, adds some funny moments in, and travels side paths between its times of faithfulness to the source. However on the whole it’s a funny, entertaining and very British movie.

- Jeremy Sadler