All you need is to be running Chrome on both your computer and smartphone (which means only iOS and Android are available). You start out by connecting your phone with your desktop, either through Chrome's tab sync feature, by scanning a QR code, or with a link. Then you either choose one of the pre-built Google pages or put in your favorite website address, and the game will break down the elements of the page to generate a game level. Unfortunately, this process doesn't always work, so some sites (like PhoneArena) will give you an error message level to play.
You control a rolling ball with your smartphone, both with tilt controls and on-screen buttons. It's an interesting game for a few rounds, and the sound is actually pretty cool in an NES type of way. We'd definitely like to see more interplay with traditional computers and mobile.