Not bad. There's definite room for improvement, but overall it was reasonably entertaining, even genuinely funny in some bits. The stuff with Grant and Lucy did go a bit long, and the ending seemed rushed, but I at least stayed mostly engaged by it.
My major complaint is actually somewhat ironic given how much I criticize Moffat for his time travel shenanigans, as this time he's gone and done the exact opposite by not taking into account the Doctor is a time traveler. Specifically, we get references to the fact the Doctor has taken a twenty-four year leave of absence because of the night he spent with River at the Singing Towers. Apparently this is why he hasn't seen Grant at all for twenty-four years. But as a time traveler, this shouldn't matter, he could easily have dropped in on Grant any time during his childhood after the quarter-century night with River, and likewise others shouldn't be able to notice a time traveler taking a twenty-four year leave of absence, how would you know unless you were somehow linked with his subjective timeline? Which, no one in this episode was, with the possible exception of Nardole.
And one final oddity, American UNIT forces answer to Osgood now?
