Doctor Who is a show capable of various different styles, from light and campy to dramatic to dark and foreboding. Yet even at its darkest, it always has a sense of humour. It might be the Doctor cracking macabre jokes in last week's “Into the Dalek” (“Top layer, if you want to say a few words”), or the zany antics of this week's “Robot of Sherwood”. It's somewhat fitting that, after a couple of rather dark episodes, the series should turn now to a light-hearted romp with Robin Hood and his Merry Men. It helps to show that, while Peter Capaldi's Doctor may be a darker, more serious Doctor, this is still Doctor Who and it can still do anything it wants.
Alas, even Doctor Who can take it too far sometimes, and “Robot of Sherwood” is an example. I would never want Doctor Who to lose its humour and it absolutely is possible to have a silly, fun, and ludicrous story that works. Doctor Who has certainly done it many times. “Robot of Sherwood”, however, tries too hard to be funny, and it does so at the expense of character. There are some genuinely funny moments in the episode, and Peter Capaldi and Tom Riley (who plays Robin Hood) have some brilliant moments together. Their rivalry is very entertaining to watch. Yet the episode frequently devolves into slapstick and nonsense, resulting in a story that, while entertaining, is ultimately unsatisfying. It's not a terrible episode and it has its moments, but it could have—and should have—been so much more.