There are two major differences here that I noticed which make the moon system in "Super Mario Odyssey" distinct from the star system in "Super Mario 64":
1. You can collect as many moons as you want in one run. You're not "reset" as it were - a short, celebratory animation plays when you grab a moon, and then you're able to continue exploring. Similar to "Super Mario 64," moons you've already collected will continue to appear as ghost items (you'll get a few coins for grabbing them again - no problem). 2. There are many, many moons in each area. They're all over the place - hidden inside of girders, across perilous gaps, on top of seemingly insurmountable buildings. There's a focus on exploration in "Super Mario Odyssey" that I did not expect.