It would be amazing if the quizzes could offer questions based on conditional logic. It would be especially helpful when using the quiz in survey-mode, as many questions asked in a survey are often informed or modified by each other.
Here's an example of what I mean:
https://www.wufoo.com/guides/conditional-logic-and-branching/. Gravity forms also offers this feature for their surveys:
http://www.gravityforms.com/features/conditional-logic/