Got 10 stars in my first day of playing this game again. Got 31 stars now, beat Bowser at the first encounter and got the 8 red coins star, too! Completed Course 1, 2 and 4 to 100%, which means I got the "secret star" (100 coins) there was well. Can't complete Course 3 right now, because I need the green box (Metal Mario) for the last star that is missing there. Next thing will be Course 5, Boo's Mansion, before I go into the underground with the key I got from Bowser.