The narrative in Long Live the Princess is in the same kind of style as, say, Mass Effect 2. In that game, you start out knowing your eventual goal (attacking the Collector base), but the majority of the game is spent recruiting the companions you will need to achieve that goal successfully. If you consider the Collector base to be the "main story" of that game, there's very little of it.
In LLtP, the Princess is your final goal, but you're not supposed to encounter her until the game's finale. What you've been doing so far is interacting with the "companion quests" of the game. These stories usually don't have anything to do with the Princess, but their success is still essential to your eventual success. And as with Mass Effect 2, the fate of your companions depends on the choices you make as you go.