In this strange complex of time and space anything can happen

That resolved out pretty well. I'm kind of glad the Alien Menace wasn't Cybermen after all. It's nice to have something new. I liked Yaz reprimanding Ryan for getting carried away and telling Barton's men the plan, and then it not just being a joke line but an actual step in the plot which helped him to find them again quickly. I liked that they acknowledged that a Master who looked like Sacha Dhawan would find it difficult to 'pass' as a Nazi general, and offered some kind of explanation for it, because that had been bothering me until they did. I liked the nods to City of Death (top of the Eiffel Tower) and Logopolis (reference to Jodrell Bank). And I'm up for a season driven by deep secrets in Gallifrey's past. I'm an absolute sucker for anything Gallifreyan.

I could have done without Ada and Noor Inayat Khan having their memories wiped at the end, though. That is a big squick for me in all fantastical fiction, and I know I've complained about it reviews of both Doctor Who (e.g. what happened to Donna) and other stories (e.g. Fantastic Beasts) before. It feels like such a huge personal violation to take someone's memories away, and it made it even worse that Ada was actively protesting against it. It doesn't even seem consistently applied, either. The Doctor has left hundreds of historical figures with their memories intact before, and I don't see that the fairly brief and confusing things they had seen would be that much of a historical problem anyway - especially since no-one was ever likely to believe them when they talked about it.

Anyway, basically OK, and I hope we'll be seeing more of Sacha's Master as the series goes on.