FWIW, xsnow runs with wayland, but ignores the windows (even when i make then floating in Sway):
$ xsnow
Xsnow running in GTK version: 3.24.29
Detected Wayland desktop
xsnow 3.3.0
Probably works better with a non-tiling WM: https://forums.opensuse.org/showthread.php/563400-XsnoW-anyo...xsnow -h says:
> BUGS
> - Xsnow needs a complete rewrite: the code is a mess.
> …
> - Xsnow does run in Wayland, but will not snow on all windows.