If you play Steam games on your computer, you can stream your games from your PC onto your phone and Backbone to play on the go!
NOTE: Steam Link requires a PC to stream the game, which is displayed on your phone simultaneously.
To set up Steam Link, follow the instructions here. You will need to own the Steam games you want to play, as well as have them downloaded on your PC before you can play.
If you do not own a PC, you can always use the GeForce NOW feature to play Steam games without streaming from a PC.