Well, that was quite good, wasn't it?
If I had a criticism it would be it felt a bit more like a Red Dwarf Christmas Special given the plot was a mashup of Better Than Life (layers of false reality and long-dead ones keeping you from the truth), Back to Reality/Earth (non-sentient alien parasites leaving people in nightmarish hallucinations) and of course Psirens (hideous alien bugs alter your perceptions so they can suck out your brains with a straw). Not to mention the sight of Santa Claus coming to the rescue (this time not with an AK47 on a minefield).
Yet I can only really say this. Steven Moffat has jumped the shark.
I use the term deliberately and I use the term accurately - in the sense not that Last Christmas was an abomination which will forever taint and ruin future stories (as the pig-ignorant morons would assume) but rather it set a standard it will be impossible to reach again. The only way left is down.
I mean, how can anyone follow on from this? Previous Christmas stories have used the iconography to varying degrees and could be set on any such holiday or even none at all. You could, at a pinch, remove the Xmas atmos from previous stories and still have a decent story (with the exceptions of A Christmas Carol for obvious reasons and The Doctor, The Widow and the Wardrobe which has no story and hardly anything xmassy about it anyway).
This story has Santa fucking Claus and Rudolf saving the day not once but twice and climaxes with the Doctor riding the reindeer around Big Ben. That's about as damn Christmassy as you can get, and even puts TV Comic to shame (Santa only appears in a cameo in part one and it's not actually Christmas).What in the sweet name of Slitheen buggery is supposed to be the next Christmas special about? What left is there to go with? Is the title of the episode a clue that there won't be a special next year? Given how utterly tenuous the links to the festive period have been under Moffat (that's three alien planets that coincidentally just happen to resemble Victorian Christmas postcards now) we've actually had a Christmas special that only has two scenes set at Christmas with the rest all being a dream!
There is the distinct sense that the bottom of the barrel has been reached but not scraped. There's nowhere left to go for the new show - at least on its present course. Look at Clara, who was turned from the fundamental generic companion into a neurotic compulsive liar and then spiralled into a complete nervous breakdown as she deliberately destroys her whole life rather than surrender control. This story shows her reaction to attempted closure is to try and commit suicide. And that if she actually tried to be normal she would have to avoided the Doctor for 62 years and die a lonely spinster with no friends. And then, for a change, she gets a second chance to travel with the Doctor.
What now? Either Clara is redefined as a new person or we have to go back to diminishing returns with her refusing to accept TARDIS life and using the Doctor as her high-maintenance charity case.
And the Doctor - as defined by the previous series - can progress no further either. Having been defined as an unpleasant git with ADD who gets absolutely everything wrong, it goes up to eleven in this story as he fails to realize he's asleep. On no less than four occasions. By the time he's yammering about missing the obvious, it drives home the joke is rapidly getting old. Are we supposed to be enticed by another thirteen episodes of Capaldi strutting around insulting people while being only slightly less useful than if he wasn't actually involved in the story at all? Even Santa Claus points out that he's an obstacle to the plot who is actually making it worse with his close-mindedness, and Michael Troughton karks it directly because the Doctor is eager to do his "I'm an antisocial bastard so Clara can tell me off" shtick. Either the Doctor undergoes a huge shift like the last two in his characterization or else he's a Little Britain sketch character doing the same thing over and over again, only without a memorable catchphrase.
The monsters have gone too far too. Moffat's grabbed the Teller, the Dream Lord and some facehuggers and come up with the ultimate expression of his nightmare paranoia fuel. A threat that only exists in those who percieve it, who are made stronger by you trying to understand it, who have already beaten you and also tend to be hideously primal horrors? After asking audiences not to blink or step in shadows or trust their own memories we are now bluntly told our own grip on reality is what will get us killed. Where else can we go but backwards? The Dream Crabs are a bigger threat than anything else this year, even the idea of the entire human corpse population turning into Cybermen then exploding. From now on, whatever the threat is, it by definition can't be as bad as the Dream Crabs, can it?
This new, darker TV show has mined these themes bare. There's nothing left. It's taken all the risks it can with an unlikeable, untrustworthy set of characters facing extreme horrors. We face either a new era of base under sieges as the same bloody plots are thrown at us like an automated custard pie hurler or else a bigger turnaround than The Liesure Hive was to Horns of Nimon. Like Pertwee's season 7, the format is unsustainable whether you like the format or not and it looks more and more like it might be time for Moffat to go - but on the other hand, the guy's reinvented Who every year, so maybe 2015 will be good?
Mind you, I said that about 2011 as well and look how that turned out.