The short stories are always told from the viewpoint of an anonymous narrator who seems to know everybody and be known by everyone despite always only being a bystander; in the radio series, he is given a name, and, indeed, the only suitable one: Broadway. The language, which is one of the great things about a Runyon short story, is a mix of extraordinarily formal and very slangy. Almost everything is told in present tense, and there are no contractions. So we get curiously musical passages like the following, from a story called "Tight Shoes":
He is a very big guy with several chins and very funny feet, which is why he is called Feet. These feet are extra large feet, even for a big guy, and Dave the Dude says Feet wears violin cases for shoes. Of course this is not true, because Feet cannot get either of his feet into a violin case, unless it is a case for a very large violin, such as a cello.
It's a kind of comic poetry. And with the right voice, it works wonderfully on the radio. And John Brown, a great comic radio actor, delivers Broadway's narrative lines almost perfectly in a Lower East Side accent that manages to sound completely practical even while saying the most absurd things.
Every episode is good, so it's hard to pick one. After some back-and-forth, I decided on "Butch Minds the Baby", in which a bunch of thieves (and Broadway, who tries unsuccessfully to wiggle out of involvement at every turn) run into some complications due to the fact that their safecracker, Big Butch, doesn't have a babysitter for his son, John Aloysius Ignatius, Jr. Big Butch has to mind the baby or his wife will put the blast on him....
You can listen to "Butch Minds the Baby" (Episode 9) at the Internet Archive, as well as all the other episodes.