The real contrast is in the interpretation of the ending. Does Faustus’ fate fit the medieval view that his damnation is justified, or does it fit the Renaissance view that he was heroic for pursuing forbidden knowledge? It is similar to a morality play, but it is actually a Renaissance play. It isn’t so much that he seeks forbidden knowledge that causes his damnation to be justified; it is what he did with that knowledge. He used it to amuse himself and earn the favor of the upper echelons of society. He also went about gaining the knowledge in an evil way, by making a pact with the devil. He had chances to repent and save his soul at the end, and didn’t. He had the opportunity to do great things for humanity, but squandered the opportunity.
So, in terms of being a morality play, you wouldn’t want to follow Faustus’ example of being a selfish jerk. In terms of his right to explore forbidden knowledge, he was heroic. In the view of many scholars, he was not damned because of his pursuit of knowledge, but rather how he went about seeking it, as well as the way he wasted it.
Enotes has some great information about this play!