Hi Kevin. Both active and passive forms are fine here.

In truth, all of the sentences are passive in the sense that none states who plays the movie. Although #3 and #4 are the only actual examples of what would normally be termed "passive voice", any sentence that does not have a subject acting through a verb has passive characteristics. "Playing" and "showing" act as adjectives, not verbs, in #1 and #2. You can rewrite #1 in ways that make this more obvious: "Playing nationwide, this movie tells a story about a fox". (verb = "tells") "This movie, playing nationwide, tells an interesting story". (verb = "tells") "The currently playing movie is nationwide". (verb = "is") When you use the adjective "playing" to describe a movie you imply that the movie "plays". But, that action is only described. "Playing" is not an active verb, so it never ever has a subject even though it can describe the subject of a sentence. In the sentence, "The playing movie shocked the audience" the verb is clearly "shocked", not "playing". Here is a truly active sentence: "The movie now plays nationwide."

I'd use show or showing rather than play or playing and both are correct.

What about screen or screening?