Where to see the current list
Start with the official Xbox Game Pass Games catalog. Then open the game you are interested in and compare the supported devices with the one you are going to play on. The name "Xbox" in the store does not mean that any item is included in the subscription. For a small selection, write down several games and test each one in the same way. Old directory addition news shows status as of the date of the message, not perpetual access.
What are the differences between subscription options?
The official page lists Essential, Premium, Ultimate and PC Game Pass. Their libraries and conditions vary; PC Game Pass is for PC. Whether you can play on launch day depends on the offer you choose, so check the current plan conditions before signing up. Separately check the included services and availability in the region. Don't transfer Ultimate features to another plan just because both titles have Game Pass.
Installation and cloud play
Installing on a device and running via the cloud are different access methods. For the cloud, separately check the supported game, region, device and subscription terms. Xbox also offers cloud play for some purchased games; this does not mean the purchase is included in the library. If a page asks you to buy a game, first clarify what type of access is described. For the first check, choose one launch method so as not to confuse the installation error with the availability of the cloud service.
Why did the game stop launching?
First, check your subscription activity and account, then check the availability of the game in the current catalog and support for your device. Access to the library is limited by the terms of the subscription and the time the game is in it. Installing files does not in itself secure the right to play forever. Before a long walkthrough, it is useful to look at the directory change messages and save your progress in the usual way. If there is an error, write down its text and check the support page for the specific game.
Sources and checks
Guides are automatically translated from Russian; interface labels may differ. The Russian edition is the original.