Yeah, as one of the designers I only had control over the assets and level design. Still, as a player, I would worry about excessive set backs in a game that's already pretty difficult, but I'm sure my friends would have better insights than I do, I would defer to their expertise if they have any additional comments on that.
I personally think that the NPCs should interact more with the world at large and have different predictable behaviors. As an end state to the game, I still think the King does what he was designed to do, but he could get more enraged with more damage. I think a Janitor that would become outraged at the chaos that could alert the king would be interesting, or maybe a Cleric that could prevent spells from being cast in a vicinity but is completely unbothered by the Blugger or the player, so as the player you'd have to figure out how to keep the NPCs in such a way that they are driven away from the chaos or the chaos is driven away from them. With the tools the player has right now, I don't think that would be any more engaging than just having the King, but if the world at large was something the player could controllably interact with with more thematic portions of the castle segmented by a variety of sizes of passage ways that could be opened or closed, I envision that could be a fun challenge of trying to manage the flow of the ball with the patterns of the people.