Let's be accurate about xbox :
You'll need an Xbox Live Gold membership to claim your games. Xbox One games are yours to play as long as you have an active Gold membership, and Xbox 360 games are yours to keep.
The greatest achievement of Google so far is not just having two business models. If you do not do it with an incomplete service and behave as if you have already earned your place and it is a more consolidated platform in the market. And all this with only 20 games. Imagine what Google will be able to do when it has more to offer.