Related to the motion sickness, I think that you could implement the camera oriented in the same axis the world is rotating. I mean "rotate" 90 degrees
First of all thank you for the compliment, for the game i thought about Captain Toad Tresur Tracker but with the ability to jump, but it being compared to Mario Galaxy it's even better! Thank you for the idea of the camera! I didn't thought about that solution to be honest. Thanks again!