One word: dull.
Sad to say, but even the funniest and zaniest of books can apparently be turned into a slow-paced, dim-witted retro adventure, with a weepy female looking all pretty and sad and spouting cliches about being a woman (Trillian?? THAT is not Trillian) and some slightly more energetic males spouting other boring stuff, all set against what looks like a mid-90s computer game crossed with my grandfather's transistor radio. I normally appreciate the "retro" effect, but it just did not work in this case. Although there are some great moments (the song at the start is hilarious, for instance), the entire film had the depressing effect of watching a lot of potential go gurgling slowly down the metaphorical drain.
Decent cast - wasted. (Especially Alan Rickman as Marvin: he seems to get about ten lines in total, at most).
Great novel to base the screenpay on - wasted.
Terrific opportunity for zany, energetic comedy - wasted entirely by a lot of people who look as bored to be up there as I feel bored watching them.
My verdict: save yourself the heartache and the money and re-read the books instead.
Tango