[jaibot]

I don't know why Google doesn't make any effort to tell users this, but: you can access all of your Google Play video through YouTube. Just search YouTube for the thing you bought, and you should find the full-length legal video marked as "purchased" that you can watch with YouTube's interface, casting and all.

[zodPod]

We rented a movie on Google Play and this was literally the only way we could watch it. It didn't even show up in our library on Google play. I have no idea but I was just lucky to have thought to check YouTube as well.