I certainly appreciated the incredibly-"meta" nature of this. The characters invented and played by Gatiss, Pemberton, Shearsmith and Jeremy Dyson (who doesn't act, so is portrayed by Michael Sheen) for The League of Gentlemen, break out of their world and into ours, as portents of doom there convince them the end is nigh - which it is, the writers having decided to move on to other things, such as a historical horror-movie, The King's Evil. On discovering they are just characters in a show, they travel to London to convince the writers to extend their story. They kidnap Pemberton and take him hostage, threatening to erase the only copy of The King's Evil. However, one writes himself into that plot, and ends up bringing the players back from that as well, as negotiations between the writers - who have taken a hostage of their own - and the characters, come to a head.
Having thoroughly enjoyed the TV series, I was disappointed by this, which had the feel almost of contractual obligation in some way, with the writers seemingly upset about not being allowed to do what they want, instead being "forced" to do more League. What worked about the TV series, was the characters were part and parcel of an entire surreal universe, into which they somehow fitted, because anything was possible. Seeing some guy staggering around a "normal" town in blackface... Doesn't quite cut it comedically. There are still some moments, but after you've endured the overstretched awfulness which The King's Evil, you'll wonder if they really are a bunch of one-hit wonders after all. There is some effort to flesh out minor characters, rather than relying on the most memorable ones from the show: yet, they were memorable for good reason, and what replaces them here falls short of being on a par. While the concept of fictional characters coming to life is interesting, the surface is barely scratched here.