I have some suggestions as to why this film manifestly fails where its predecessor did not, and where the TV story succeeded. First off, the TV series has an ensemble of regular characters with established relationships; the film loses time and momentum setting that up (and also has no particularly good reason for it). Second, the switching round of the narrative strands fails to work in the film's favour. Here, Tom and Louise, rather than Ian and a local, head up to Derbyshire in the Dalek saucer; and Dr. Who and granddaughter Susie travel by land separately rather than together. (Susie follows roughly the route of Barbara on TV, accompanied by Weir's Scottish resistance fighter.) Opportunities are missed to generate much spark between Tom and Louise, let along their terrestrially travelling friends. Of the good scenes from the TV story, only Dortmun's last stand and the treacherous women in the woods survive, and are done less well. (The women are played by Eileen Way and Sheila Steafel.) Finally, the geology of the Daleks' plan actually - and this is difficult to believe - makes less sense than the original TV version.
Anyway, this is really for completists only.
(I have a memory of seeing a version where Roberta Tovey's character is locked out of the Tardis at the end à la Carole Ann Ford's departure, but I guess I must have dreamed it.)