YMMV / Doctor Who S36 E9 "Empress of Mars"

• Ass Pull: The TARDIS leaves with Nardole for literally no reason except to leave the heroes without an escape route. This arose in large part because Nardole was a late addition to the Series 10 Team TARDIS, well after this script was put into development/writing, and it was easier to simply write him out than find a role for him to play in the main action; plus, the resultant in-story crisis allowed the Missy-in-the-Vault arc to make further progress.
• Continuity Lockout: Quite a few New Series fans who were unfamiliar with the classic era were left confused at the surprise appearance of Alpha Centauri; while this wouldn't be too much of a problem, the fact that it was vital to the story's plot and didn't receive any explanation for the uninitiated meant that how well it was received from viewer to viewer was heavily influenced by whether or not they know who Alpha Centauri is.
• Special Effect Failure: The establishing shot of the NASA exterior at the beginning of the episode is very obviously computer-generated.
• They Wasted a Perfectly Good Plot: The teasers for the episode focused heavily on the moral dilemma the Doctor would face in this episode: normally the Doctor defends humans from alien invasions; but this time the humans are the invaders, so whose side is the Doctor on? In the episode proper, the Doctor ponders this ethical dilemma for all of thirty seconds, at which point unrelated plot developments cause the dilemma to be completely forgotten.
• Unexpected Character: Two — Missy is called upon by Nardole to get the Doctor and Bill home, and Alpha Centauri appears as The Cameo in the denouement (voiced by their original actress, no less). With regards to the former, Michelle Gomez was not listed as appearing in this episode in any capacity.
• Win Back the Crowd: A downplayed case — it wasn't regarded as highly as some of the early Series 10 episodes by most critics and viewers, but many found it something of a course correction after the ambitious-but-flawed Monks Trilogy hurt the season's momentum. It was also much better-received than Mark Gatiss's previous effort for the Twelfth Doctor.