You'll find the cards are more just an aside, adding to the story of the game rather than driving it. It's played in a community fashion, so progress is made in many ways, such as contact with the characters, but also often drives itself as the characters go about their lives and react to situations.

The cards are mainly just for the fun of solving and to get points on the leaderboard (which has no real influence on the story or game). The description in the article really can't do the game justice, come on over to #syzygy on irc.chat-solutions.org if you want to learn any more (Just tell 'em Six sent you). They always love new people in there.