Doctor Who is never good when it's rushed. We all learned that during series 7. Until now all the episodes had consistency. Some were amazing, some were OK, but this series had the potential to be one of the best Doctor Who seasons in decades. But it's ruined again.
The idea for Kill The Moon was just ridiculous. The writer, Peter Harness, tried to create an interesting premise but he didn't have the capacity of conveying a decent pay-off. Fast paced, meaningless allegories about abortion (come on, we're not in the 90s anymore) and stupid ideas about science (seriously, he could've just checked Wikipedia about prokaryote organisms, unicellular organisms and spiders) made everything awful. The silly science really bothered me. Doctor Who is not a sci-fi show, it's more like sci-fi fantasy, but what Harness did in Kill The Moon was to insult the viewer's intelligence. I hope he never writes for Doctor Who again.
I feel sorry for Peter Capaldi though. He's probably the best actor to play the role since Classic Doctor Who and we've seen how amazing he can be in Deep Breath, Into The Dalek and Listen. It's a shame we won't probably get a new show runner or decent writers any time soon. The roller coaster will continue...