Unveiled during a dedicated event at the Game Developers Conference in San Francisco, Stadia is the firm's new online service: a "Netflix for games" if you like.
It is designed to offer triple-A gaming instantly and potentially on every connected device available.
"Think about the web, you can share a link and it loads instantly. We want games to feel that way too," said Google CEO Sundar Pichai.
Stadia - formerly known as Project Yeti - uses technology tested during the Google Project Stream trials at the end of 2018.
That used a Chrome browser to stream a version of Assassin's Creed: Odyssey on PC and Mac. However, at launch Stadia will be available across laptops, desktops, TVs (via Chromecast), phones and tablets.
It will run instantly, including some interesting, cool features such as being able to jump straight into a streamed game from a trailer on YouTube. There will also be cross-platform play on games, so players can take on others on PCs, Xbox One or PS4, for example.
In addition, a dedicated Stadia controller will be available that connects directly to the internet through Wi-Fi - not your device. That reduces latency greatly as it doesn't need to send control codes to the tablet, smartphone, etc. By sending the codes straight to the server centre, it cuts out the middle man.
That also helps run Stadia games on slow, low-spec devices.
When Stadia launches, Google claims that it will be able to stream games in up to 4K HDR and at 60fps. It has been successfully tested at 1080p 60fps.
And further in the future, the company plans to stream games in 8K HDR at 120fps.
We're still awaiting a price, but Google plans to release it in 2019 in the US, UK, Canada and Central Europe first.