Here's the arcade addon for Invision running in D6:

http://astrosturf.com/games.php

That's just a do-nothing test site of mine. The arcade mod for Invision is the best I've seen. There's almost 10,000 games available, but it's pretty easy to narrow that list down to 500 or less. More in this case, is not better.

I have several options for multiplayer Texas Holdem, on my D7 site, as well as some mulitplayer board games.