Some good, some bad
I liked lots in the episode - the filmography was excellent. The alien bugs were also believable. What I hated though was that decision when they could have gone with some simple alternatives and made it far more believable i.e
- Clara follows earths instructions and does not intervene, the Doctor suddenly appears and intervenes and prevents the action along with some comments about humans wanting to kill everything. This would have made logical sense and would have made Clara's later attack on him more reasonable
I don't think I was alone in thinking when Clara made her plea that 90% of people would not have been watching and even if they were 45 minutes was not enough time for governments over the planet to get the various grids switched off even excluding households) so she would get an incorrect response as no intelligent human would take that risk with the lives of their children. I was relieved when the earth said 'Kill' and then she ignored them........
Alternately they could have then shown the practical obliteration of life on the planet also allowing the Doctor to say 'strange choice' and Clare again to argue.
As it was they took almost the worst fluffy line possibly though they could also have announced that if everyone on the earth sent good thoughts the disaster would be averted (oh wait that's been done).
I was not so bothered about mass and flying space dragons, the strange lack of space ships, the fact the Doctor was letting a race he knows always uses force make a decision he wanted to go an illogical way etc etc.
Over all I like the darker Capaldi and am hoping the series can last its long winded companion wind up as Clara leaves at Christmas. I hope they dont swing the other way and make him or cheer and light with the new companion...