I find fossilized micro civilisations fascinating, so the Grand Duchy of Fenwick, in their medieval armour, traditional European costumes and nineteenth century suits, was a nice spectacle.
(Peevish rantlet: Why on earth did they keep pronouncing the W in Fenwick though? It's a British film so surely they'd know not to!)
It's quite entertaining when they accidentally-on-purpose go to war with America, but as old comedies about tiny made-up countries go, Passport to Pimlico was better and more likeable – and more logical.
Despite having read lots about Peter Sellers just now, and reframing him as “troubled and difficult” rather than “an arse” I still don't quite click with his style of comedy. Though seeing him play three roles in one film, there's no doubt about his chameleon acting skills, with completely different body language and presence in each.