This movie is a blast. If you're a fan of Shakespearian situational comedy (Twelfth Night, Midsummer Night's Dream, etc) then you're in for a treat. And please note that when I refer to Shakespeare, I'm talking about the original plays, not some stupid Kenneth Brannaugh romp.
The plot weaves a wonderfully tangled web of lies, misunderstandings and mistaken identities. The characters are just plain fun to watch. And director Lasse Hallström pulls off what so few people are able to do: make a comedy that doesn't offend anyone. Well, actually I think some Catholics may be offended at the uncomplimentary portrayal of the 18th century papacy, but from what I know of history, it's well deserved.
But this leads me to another point. Don't expect history, OK? A few reviewers seem to be upset by the poetic license Hallström takes. C'mon people, it's a fantasy. It's no different from the film AMADEUS which trounces all over historical fact but gives us a fantastic dramatic fiction in return. I admire creative writers who can turn history on its ear.
So yes, this isn't the erotic, decadent Casanova you may be expecting. In my opinion, that portrayal is hackneyed anyway. This is a much fresher approach. So put down your history books and enjoy the picture already.