play.google.com/googleplaygames
Basically it's an Android emulator developed by Google with 40 games available at launch, and more to be added. Rather than try to emulate everything to make a cell phone app/game work in the emulator, Google is working with the game devs to hopefully give a better experience. It does connect to Google Play, and things like game progress sync across devices using the same Google account.
Requirements are hardware virtualization turned on in the BIOS, Win10 or 11, SSD with 10GB free, at least 4 core CPU, 8GB RAM, & at least the equivalent to an Intel UHD Graphics 630 GPU, which stretches all the way down at the low end to the Pentium Gold. You'll have to look at the docs or manual for your device' BIOS to see how to turn on hardware virtualization -- *generally* you keep pressing the Delete or F2 keys just after turning the device on [when it's fully off, not sleeping or hibernating] to get into the BIOS, and you'll find all sorts of info on getting into the BIOS from Win10 & 11 if you Google. GooglePlayGames will also turn on the Windows Feature: "Windows Hypervisor Platform" [Control Panel -> Programs and Features -> Turn Windows features on or off] requiring a restart, so you cannot use VirtualBox [*technically* you can, but IMHO it's unusable].
It's not a lightweight install... The download is a downloader that's less than 2MB, but the Windows Installer setup file [.msi] is a bit short of 800MB, & the program's folder will be around 2.5GB. A 2nd folder is created in Program Files (x86), initially just with the Google Updater if you don't already have it installed with the Chrome Browser. It uses .NET, and added around 4k new registry entries -- not just rewriting one or two hives -- when I monitored the install in a Win10 VM.
You start by setting up your profile, agreeing to Google's terms, then signing into your Google account in a separate browser window. That done, the Home screen is where you find and select games, with a large Install button on the page for each game that turns into a play or start button once it's installed. Click the 3 dots next to that button to uninstall. This Is A Beta -- the 1st game I tried didn't work.
Over the coming days/weeks I expect there will all sorts of additional info, e.g. sideloading.