Central Premise Recycled From: "The Pandorica Opens" via "A Town Called Mercy" and "The Parting of The Ways".
Moppets, doggerel rhymes, character aging while other characters stay
young, the Doctor having a fling with a sexually rapacious older woman, a
future crypto-Catholic church that's a lot more sexually liberal, the
Doctor as Wild West sheriff of a town with a daft name, Scottishness
when Capaldi turns up, the Greatest Hits Reel featuring the Crack in the Universe, the Weeping Angels, the Silent, the Dalek dickheads, Amy. A bunch of the Doctor's enemies ganging up on him.
Not Stolen from RTD, Honest:
Pretentious narration track opening the episode. Companion inviting
Doctor for Christmas dinner with the family. The companion's mum is an
interfering bitch, but her surviving grandparent is rather nice. Clara
lives on the Powell Estate these days, apparently. The Doctor in old-guy
makeup. As in "The Parting of the Ways", the Doctor tricks the
companion into going back to Earth to keep her out of danger while he
faces the Daleks, though Clara's rather more passive about this than
Rose was. Companion travelling by hanging on the outside of the Tardis.
Daft sobriquet for the Doctor ("The Man Who Stayed for Christmas").
Naked people (somehow linked with regeneration-- Captain Jack in "The
Parting of the Ways", and the Doctor in "Journey's End"). The Doctor not
regenerating into another form straight away, but taking the time for a
protracted goodbye. The Doctor in love with his first companion (since
he cares enough about Amy that it's her he sees as he regenerates).
Post-regeneration Doctor talking about his new organs.
Evil Household Objects: None, but there's a slightly undercooked turkey.
Doctor Who! It's the question the Crack in the Universe is asking.
Hats! The wig's a good variation. One of the Christmas Townies wears a smoking-cap, a garment whose design originally derived from the fez.
Moppets! Too many of them around Christmas Town.
Clara's Job This Week: Christmas dinner chef and needy crushed-out girlfriend.
Murray Gold's Christmas Number One: He doesn't get one. Has there been a budget reduction?
Gratuitous Continuity Frakups:
Clara sees a Silent, and doesn't immediately lunge for it and kill it.
The Angel that trapped River in "The Angels Take Manhattan" gripped her
wrist but didn't send her back in time because the Angel was too weak to
do otherwise, but that's apparently been forgotten in Clara's similar
encounter. Once again the designers seem not to have noticed that those
semi-circular things in the Tombs of the Cybermen were climbing aids,
not design elements. In "Asylum of the Daleks", the Dalek dickheads were
created through exposure to nanogenes, and yet here, though the Doctor
and Clara are undoubtedly exposed to same aboard the Papal Mainframe,
they show no signs of changing. Regeneration energy is now powerful enough to take out a fleet of Daleks. Although it's established in "The Day of the Doctor" that the earlier Doctors in multi-Doctor stories don't remember their events, somehow the Matt Smith Doctor knows that the Jon Pertwee Doctor stole the Seal of the High Council from the Master in the Death Zone. If the events of Trenzalore have changed so the Doctor didn't die there, then the Intelligence can't have gone to the Doctor's tomb in "The Name of the Doctor" and Clara can't have done her trick of splitting along the Doctor's timeline, and thus goes from being The Impossible Girl to being The Irrelevant Girl.
Things That Aren't Actually Continuity Frakups:
Really, people, there's no problem with the Doctor leading the Silent
into battle-- so long as *they* remember what they're supposed to be
doing, it doesn't matter if *he* does. Although it's not stated in the
story that Clara's "mum" is actually her stepmum, it's not impossible,
which explains how Clara suddenly has a mother despite her mother's
death being a plot point last season. Likewise complaints about Clara's
middle-class family living on a council estate overlook the scenario
that it's Clara's flat and, like many budget-conscious young
professionals, she's renting an ex-council property.
We learn what it actually was that the Doctor saw in Room 11 in "The
God Complex" (the Crack in the Wall), and an explanation of why the
Doctor is the thirteenth Doctor despite only 12 appearing in "Name of
the Doctor" (Tennant managed to regenerate back into himself).
Other Frakups: The Doctor spends 300 years in Christmas Town, and yet
somehow the culture, economy and political system of the place fail to
change? Apply that to England in 2013, and we'd be living in a country
with a politically active monarch, voting rights restricted to
property-holding men, slavery legal, no steam engines or electric grid, and periwigs and frock-coats the height of fashion.
Why does the Punch and Judy show feature a Monoid as a villain-- they
weren't actually monsters, just an enslaved species, so it's a bit like
featuring an Ood as a baddie. The lighting filters on the estate sequences mean that Clara's supposedly cooked turkey looks half-raw.
Out of the several possible scenarios through which the Doctor might
gain extra regenerations, they have to pick the most banal.
Nostalgia UK: The usual gratuitous Doctor Who continuity references, e.g. mentioning Terileptils. Also gratuitous cross-programme intersectionality as Clara's family watch "Strictly Come Dancing".
Don't know if it's deliberate or not, but it's really funny to watch
the sequences with little Amelia in her red wellies and hat running
through the Tardis, while thinking of Don't Look Now.
Item Most Likely to Become a Toy:
On the basis of past Chrismasses, I'd say "nothing". However, the
wooden Cyberman is exactly the sort of variation CO seem to like (q.v.
the rusty Cybermen and transparent Angels of earlier years), so it might
actually make it. Also they usually do a post-regeneration Doctor figure, so we're likely to get a Capaldi in Matt Smith's clothes.