So onward to spoilers:
-blowing bubbles in the broken tub
-Dr. Quackz and his brand of comedy
-Pagies in the balloon room
-the skulls (specifically in the cosmic world)
-that trowser snake
-Gloomy Grotto because of how challenging it was
-that it is a 3-D platformer that recalls imagery and game structure similar to our old favorites
-I'm a fan of collectathons and 100% completion so that too!
I think I'll start there but I love a lot more from it and I hope you do too. Feel free to add in the love.