Smile- Similarly to Doctor Mysterio, this episode sounds completely stupid in concept, yet the execution manages to make it work.
This one is fun. Capaldi and Mackie are fantastic, and the dialogue is great. It's also surprisingly funny at points. Visually, this episode is great, and the music is good.
The emojibots are stupid, but just the right amount of silly to be entertaining for the most part. I find it's more about how the characters react to them that makes them funny, rather than what they do by themselves. They aren't visually appealing either, and I think they look almost cheap. The pacing is excellent for the first two thirds, but I think it falls apart during the final segment. The human characters are not interesting in the slightest, so when the story begins to focus on them I tend to find myself checking out of the episode. It's not awful, but I find it rather bland. The episode is saved by the first two-thirds.
The lack of a threat does this one no favours either. The Vardy are supposed to be the villains, but they do not feel as threatening as they should, so when they start to become more outwardly villainous towards the end it just seems silly to me. The idea of the Vardy killing the humans because they perceived grief as a disease is an interesting one, but these ideas clash so much with the comedic tone that the heavier stuff never feels as dramatic as it should.
This episode is a decent one which I can watch at any time, but I tend not to because there are so many better episodes. It's well paced for the most part and has some good laughs, and is carried by the performances from the two leads, but once the story expands and more characters are introduced the pacing suffers. It's not awful but there's not enough to it to make we want to revisit it. The bland side characters and weak villains also don't help.
Overall- 6/10.