It depends on what you're asking.

If you're talking about playing natively games on the Game Pass, you can't as of right now there's no Xbox app to download and launch them on Linux.

Otherwise, if you meant streaming games from the cloud through Game Pass, then the answer is "it depends from your connection", but i am quite satisfied with the experience so far. I'm on a 1Gpbs optical fiber, games run well, i get some-to-zero graphic artifacts and even though you can feel some baseline lag, for most games it's fine and you'll get used to it in a minute or two.