If a game doesn't work in Wayland, you could always launch it in gamescope[1], which AFAIR doesn't expose WAYLAND_DISPLAY by default, so games should treat it the same as an X11 desktop.
I haven't had anything flat out refuse to work on Wayland, but unfortunately Discord won't work right. It runs, but it can't detect that you're AFK any more, so you stop getting messages on the mobile app. It's a bummer because otherwise I would love to use Wayland.
[1]: https://github.com/ValveSoftware/gamescope