As a fan of the old 1980's text adventures (retroactively entitled Interactive Fiction, or IF), I find that Action Castle scratches the itch to play a text adventure in a group admirably. It's quick, easy, and very simple. The price matches the complexity of the game, but don't mistake its simplicity for being inelegant. The genius design elements are the way the IF is translated from a parser with definitions and one player into a group game with a Game Master (called a Parser here).
If you're looking for a quick game to entertain friends in between campaigns or a beer-and-pretzel substitution for game nights that are a wash, take a look here and at all the Parsely games out there. It's well worth $2.
[4 of 5 Stars!]