I normally wouldn't post this here as it really isn't a Mac game as such, but a massive multiplayer singleplayer game that can be played online. Jick and Co. have been constantly updating this game since 2003, and they've always kept the game accessible. The story-driven based word game they developed for iOS, WordRealms, sadly is not accessible and probably can't be made accessible.
Previously when playing in Safari for the last few OS X versions, after logging in one would be presented with either one frame when there are three frames, or in most cases, an empty HTML content and you'd have to refresh the page and fiddle with it to work, and even then it would be inconsistent.
Now I'm happy to report that VoiceOver, for the most part, plays nice with it now. I've hit a few snags here and there on some combats, but otherwise I feel pretty confident in saying that VoiceOver users, whether you're a new player or you played previously on Windows and want to come back, the game has changed quite a bit in the last three years or so and I highly recommend joining Guardians of the Six Pack clan.
Here is a link:
Feel free to KMail me, Orinks, with any questions.