The worst I can say is that it felt like a retread of 'Fear Her'. This one didn't even have a CGI killer doodle, so it must have been saving the effects budget for something else (although granted Confidential showed them making alot of overscaled furniture and props).
It was pretty obvious this one had been pushed back from its original place. It felt a bit off with how heavy the season arc has got and the revelations of last week.
The story wasn't bad but this was very clearly one of those episodes where scare factor was prioritised over story. Which makes it all the more awkward when the scares don't hold up. I'm sure this will give kids some unease but every 'scare' seemed to amount to 'Don't open the door now!'. There were some creepy moments like the people being turned dolls (let us never complain about the sculpt on Character Options figures again) but I think alot of the fear was lost when it became clear George was unknowingly controlling things. An episode like 'Blink' was consistently scary and then ends on a reveal that suggests the entire audience is now in danger. Things got defanged pretty quickly although I partially blame that on the show's formula. 99% of the time, the show will get scare factor out of an alien or monster before revealing they're just misunderstood. I couldn't be scared because I was almost certain we were headed for that kind of end, which we were. I'd welcome a few more 'I'm a straight out space nasty and the Doctor needs to stop me!' stories.
I probably sound harsher on this then I meant to but overall I found this to be filler that didn't even bring the promised scary.