It's funny how people apparently either hate or love this movie. Every user comment either gives it a "1" rating or above a "7" - it's a good thing we have the average, then, which in this case for once is actually very accurate: this movie is worth about a "4".
It has funny elements, though not many for a movie that's supposed to be a comedy. The portrayal of Celtic-Britannic culture (incl. some Picts) is entertaining and even a little educational, and the movie's main strength lies in its realistic portrayal of what would happen to someone who tried to rescue a family member from being kidnapped by the Romans: she becomes a slave herself.
The funniest thing about the movie is probably the way we have Worthaboutapig crossing the English channel and then instantly thinking that the Roman colony she finds there ("Boulogne" = Paris) is actually Rome itself. For some ignorant clan member who's never been to the continent before, and certainly never seen the capital of a major civilization (to say nothing of a map), that's actually extremely realistic. And the anachronistic line "When in Rome...!" just has that extra little punch, when we know that she isn't actually in Rome after all.
There are a bunch of details to like in this movie - the production values, for instance, and that terrifically nonchalant German gladiator, Schlaffwaffe -, but it's just not funny enough, overall. It's too understated, has very few scenes approaching the memorable, and just strikes me as too self-indulgent. Fart and crotch jokes abound, which are tasteless and unfunny. The characters are cardboards. As a whole the movie is a disappointment, but at least it marginally holds your interest throughout. That, at least, is something.
