I have been playing a bunch of their Java games that say they are incompatible with unix & macintosh computers.
They work great, sound and everything, except for the highscores (requires IE 4.0 or later). Since I am not even spoofing the user agent, I am willing to guess there is a chance of that working too.
But why is yahoo saying it doesn't work? I have not a guess of a hint of a shadow of a reason.