I like the new prankster comet thing, how they combined purple coins into it and added more variety. I remember in SMG all but 5 of them were either daredevil run of speed run. Only 3 were cosmic race and 2 were fast foe. Now the more variety is better.
The 100 (or 140) coins on the tree slid was a pain in the ass for me, that's probably the most lives I've lost on a single mission so far. It was really cool though. But I took Luigi and I felt like his handling was a bit too slidy so it was really hard to keep in a straight line. I don't know if I'm the only one but I found the only way to get the coins was to wiggle back and forth.