I got this for Christmas. Kendra and I gave it a try by introducing only a few elements to the standard game.
2 dungeon sections
The Dragon Slayer sword
As a side note, I really enjoy Dungeon Twister. My only complaint is it's much more rule-heavy than I anticipated, so we don't play a lot. In our games, I usually win because I'm the only one who really knows all the rules. Not fair, I know, but it sure beats explaining every single rule.
Since we didn't have the teleportation rings, the dragons sat in their spaces the whole game. There wasn't much chance we'd kill anyone with our dragons, since no one was actually going to move in front of them. Instead, the dragons turned out to be targets, as they're worth 2 victory points.
I ended up getting my cleric and goblin out earning me 3 points. I think spun a chamber and zapped the dragon with a magic wand to win. Kendra wasn't too happy since she didn't see it coming. I may have ruined my chance of playing this again!
My conclusion: The game is great fun, but I'm not too interested in more two-player expansions. The base game and this one offer me more than I'll ever have a chance to explore. I want to get the 3/4 player expansion though.