I played it a bit in college.

It's not a "game" the the traditional sense, like Monopoly or Scrabble. It's role playing in the extreme, and that's what's got the religious fundies in a snit. You can play an evil character. You can also play religious characters (monks) who can kill with their bare hands.

It also has no definite end - you can explore the "dungeon" as long as you want - or until your character is killed. Sessions can last for hours or days, depending on the stamina of the players.