Hey there. Sorry I’m slow to respond…I just learned about this forum last night 
It turns out that the games are there, but there’s some re-draw bug that I introduced at the last minute. I will try to figure that out and get in fixed in the next push. Basically, if you click in the list, and then hit up or down on the keyboard a dungeon will be selected, and the Join button will become active. I’m as puzzled as anyone about what’s going on.
Now, note that when you actually join a Dungeon, it won’t so much be “fun”. The levels that are in there right now were the ones we used to do a lot of last-minute testing, and I never had time to go back and write real content. Again, that’s the plan for the next release. If anyone wants to have fun writing levels or new sprite maps, let me know! The real purpose of the Hack game is to provide a pretty rich example of both client and server-side code. I hope it’s useful…
Also, there are two Dungeon maps here. One is repeated 12 times (again, for stress-testing purposes), and the other is based on a game from another web site some folks may recognize. You need to pick the right kind of character to play the latter level, or the sprites won’t match up. I’ll leave it as an exercise to the reader to figure out this mapping 
seth