With mobile devices sporting big, beautiful touchscreen displays, it only seemed natural to expect that Google's Stadia gaming platform would one day support this input method as a way to play. Although Google hasn't made any official announcement about such a feature, Redditor SmashShock was able to hack together a working version of mobile touch controls for Stadia that they're calling TouchStadia.
Essentially, TouchStadia is a Chrome extension that places the Stadia Controller's key layout on top of the display while accessing Stadia games on a compatible mobile device. In order to enable this hack, users have to access Stadia by logging onto stadia.google.com via Chrome, request a desktop version of the site, and then use custom javascript that activates the touchscreen interface.
This obviously isn't the most ideal way to play Stadia. In fact, depending on the game, trying to tap R/L buttons and A/B/X/Y buttons with a single thumb is downright frustrating. However, this method is currently the only way to use Google's cloud gaming service on a mobile device without having to physically connect a Stadia Controller or link a Bluetooth controller. If you'd like to enable TouchStadia on your compatible mobile device, you'll have to follow the steps outlined in this video:
We were able to get TouchStadia working in minutes on a Pixel 3a XL. If you do try it out, keep in mind that the custom javascript has to be pasted into your mobile Chrome browser every time you visit stadia.google.com, so keep this code handy if you fancy playing Stadia with touch controls.