There are many games on Steam with mobile ports, from indie games, to retro games, many have fully functioning ports designed for mobile, however the one time I used the steam' link app for half life it was terrible, and part of the reason I even play a mobile game is for it to be an on-the-go experience, when I'm far away from my pc, and the app is dependent on that wireless connection, and it feels jarring when you're playing a game which you know has a mobile port. I believe the best solution is to add a mobile launcher that allows you to play any games you have in your steam library that have mobile ports through the launcher, it could slowly be expanded with it creating an incentive for developers to develop their own mobile ports, as it could bring in an entire new market of gamers through it. Please consider this idea.