Leading up to Jelly King, there are 4 rooms, each with a key. 3 of those keys are needed to move on, and the 4th unlocks a treasure room.
Leading up to Vanaduke, there are 8 captured Sprites. 6 of those Sprites are needed to move on. And every team I've gone in with so far has pointed to the same two rooms and said "Those are too hard, and not worth it."
So, my question is pretty simple: is there any benefit to rescuing ALL of the Sprites (such as there is to getting ALL of the Keys in a Jelly run)?
Once the my team rescued seven sprites just for the fun of it and the only discernible difference was the added crowns and heat.