The full-size Xanadu won’t be out for quite a while. When I do finish, it will probably be in a browser-based form. Meanwhile, if you’ve got a Classic emulator sitting around—or a very, very old Mac—you might try the two-room demo. Or, if you don’t feel like downloading, check it out right now in your browser.
Disclaimer: I found the original demo file in the deepest recesses of the System 9 directory, and have no idea whether it still works. But I zipped it up anyway.
The demo covers two adjoining rooms from one sector of the game. I picked them because they’re especially densely coded, so you can spend some time there even without a puzzle to solve. One room is mainly entertainment; the other ties in with the overall storyline.