Google Play Movies is one of the apps in Google's catalog that doesn't get a lot of attention. There is sometimes an update to the app here or there, but in general Google focuses more on adding more content to the Movies & TV store rather than updating the app. But, today brought a pretty nice new feature to the app, adding info cards similar to Amazon Kindle's X-Ray
Like Kindle X-Ray, while you're watching a video on Play Movies, just pause the video and Google's favorite cards will pop up to tell you who is on screen and give you links to more information about that actor. You'll get the general personal info card with the name, birthday, and home town (assuming all that info is available), and you'll also get a card with links to other movies for the person.
It isn't available on all movies. Google says it's available on "hundreds of movies" with more added all the time. You'll need to be running Android 4.0+ as well. If you want to get the update, just head over to the Google Play Store