Punting Down the Thames
The play is set in London, mainly at locations along the Thames, like Thomas More's house, the Tower of London, and Cromwell's office. More lives in Chelsea—now a posh district and former nexus of "Swingin' London" in the '60s.
But in the movie it's totally pastoral and bucolic. It's full of lilacs. It's very different from the grim governmental quarters of London, where Cromwell sits around concocting nefarious schemes.
More and his family have a nice spread—a country manor right on the banks of the Thames. By contrast, a grim atmosphere pervades the court where More is tried and the office where Cromwell interrogates More.
We get the sense that, even though the bad guys are technically profiting and thriving, they're losing their souls; certainly, the places in which the find themselves indicate that the states of their souls are not very positive. Even when More is executed, a pretty, natural environment seems to surround the Tower of London. He brings his own joy with him, and it seems to have a definite impact on the setting.
That Old Time Religion
Also, as far as the time period goes, this takes place during the reign of Henry VIII—an era of upheaval. Specifically, the action spans the years from 1529-1535. This is before Shakespeare would revolutionize literature and before the Pilgrims would strike out on the Mayflower (just to put it in context—Shakespeare wrote during the reign of Henry's daughter, Queen Elizabeth I).
England isn't a Protestant country yet—although there are a bunch of Protestants around (Thomas More ordered a few executed). But Henry VIII would change all that through the very divorce and marriage depicted in the film, which caused him to break with the Catholic Church. Thomas More, loyal to Catholicism, couldn't get behind that—to him, it seemed un-Godly.
So basically: The movie situates its action in the middle of one of the most crucial periods of transition in British and in world history.