Most people's gripes seem to be with the unrealistic "happy" ending, which changes the whole point of the original story. The first part of the film was pretty good, but at the end I felt I'd watched a very poor film.
It's Listen Again - so you get a clip of the tail end of the previous programme and then the continuity announcer first.
(BTW, the previous programme is James Follett's Earthsearth - a brilliant sci-fi that would make a great film. Unfortunately Listen Again is part way through the series and you really need to hear it from the beginning to make any sense of it)