Games with Unknown Goals

Unknown to ALL players? Or just unknown to some players?

Flux has a goal that's not known when the game begins, but the goal is created (and changed) through the game.

Shadow Hunters has a goal that's known to each individual player, but none of the other players know what your goal is.

Later versions of risk also have individual win conditions that are hidden to the player with them.

Yamahako already mentioned Fluxx from Looney Labs, but they have a number of others which also have hidden goals per player:

In Aquarius and their new release Seven Dragons, each player has one of the five elements/colors as their secret goal, and are attempting to create a set of 7 conected tiles with that element.

In Chrononauts each player has three possible ways to win. Two are secret, and one is open. They have a Secret Identity, and are attempting to get back to their original Timelline. They also have a Secret Mission to collect a specific set of artifacts from the past and/or future. Or they can repair enough paradoxes in the time line to increase their hand size to 10 or more.

Back to the Future has a similar mechanism where you have a Secret ID and your are attempting to set the timeline up to be most favorable for your character.

Of course, then there is Are you a Warewolf & Are you the Traitor. Where based on your secret character card, you will be striving for a different goal in the game.