Well, in the Hobbit (the book) the narrative is rather forced up on Bilbo, in the form of an uncomfortable visit from Gandalf.

If there's a boss, maybe we can be given a reason to go visit the boss, or told why we want to defeat the boss, or like Mario, why the boss had kidnapped the princess, so we have to defeat the black knight - or big Monkey?

Setting up a basic tension up front guides action. Otherwise I'm just moving around and dodging stuff but not exactly sure why?