Together you are trying to complete a quest before the Dreamer awakens, choosing the path to follow, making decisions, fighting monsters, rolling dice, and trying to reach the end of the adventure in time. If the Dreamer rises before the end of the quest, you must start the adventure again, but the heroes now having gained experience that will make them more powerful.
DreamQuest also includes an illustrated book that you can use to record your adventure, personalizing the record for recollection later.