I fully trust they'll find a solution to the 200 feathers situation -- something that "feels" right with their professional intuition and playtests well.
They could do the thing where if you fet 30/30 feathers in a zone/section of the world, then that's the high score and they all turn red in that area. You can still collect red feathers but they don't count for anything. However if you do get all 200/200 in one go, you get an achievement or sticker or something.
If anything worries me 25 pagies to start sounds a big difference from Banjo ... curious how that will look