My personal preference is that I would have liked more Edward and Tubbs, rather than Geoff and Hilary Briss, but the result was an achievement that worked on many levels. As in the third series, there is a single storyline around which things are written: the characters in Royston Vasey have been abandoned by the writers, and through the crypt in Royston Vasey church, like Mr Benn, the TARDIS, or the Wardrobe, they are transported to another universe - that of their creators.
Some scenes are straightforwardly hilarious, such as lighting the crypt with Pauline's pen, Herr Lipp's "good costume", the "real" butcher's shop, or the row in the London Eye capsule; others are funny in a more gross way. Back in the seventeenth century, David Warner is an excellent guest star as the evil Dr P; I particularly liked the door handle, which reminded me of Murder by Death, though it was also Hogwarts-esque. As the film reatches its end, the question of an objective reality really takes off. For once, Geoff doesn't ruin everything - or does he?
People who didn't like the TV series are not going to go and see this film, so its success will depend on the fans: I imagine some (like me) will enjoy it, though others will dislike it with varying degrees. There's a limit to what you can - or should - do with so many one-joke characters, but I think they have pulled it off.