Wow! I'm pretty damn happy with this one. The bulk of the episode was nothing all that remarkable, and it definitely reminded me of other episodes of Doctor Who in the past. It wasn't exactly offering anything all that new. However, the ending definitely offered something quite new, and the buildup to it was excellent. Let's take a look!
Cons:
Like I said, there were elements of this episode that felt like I'd seen them before. Aliens show up and threaten to destroy the world, the Doctor says no I'll stop you, and it all comes down to a few key humans making the right decision to prevent disaster. The Doctor is always right, the humans are always wrong, and they fail unless they listen to his advice. In this case, it's the heads of the three largest armies in the world: the U.S., Russia, and China. They decide to work together, which is good, but they decide to capitulate to the aliens, which is bad, and they all die for their trouble. A little simplistic.
We also have this moment where the Doctor encourages the three powers to strike against the mysterious pyramid that has shown up in their midst, to show their strength against this alien threat. Nardole and Bill both act shocked and appalled that the Doctor would want them to try a violent tactic. Okay, yeah. The Doctor is a pacifist and so any hint that he might be violent is seen as a crazy deviation from the norm. Sure, except for I feel like I'm being asked to be shocked about the same thing over and over and over again. Moffat's Doctor frequently resorts to violence, or at least doesn't stop others from trying it. Bill's outrage in particular kind of rubbed me the wrong way, because I feel like we haven't seen enough of Bill learning the Doctor's "code" as it were. Does she really know him well enough yet to understand that this behavior deviates from the norm?