New Super Luigi U: Peach's Castle-4 -- Firefall Rising

It's raining fire in this level and the stone platforms you can stand on will disappear, then reappear. That is, if fireballs haven't destroyed them yet. Cross the disappearing stones to the right side, then climb the wall. The first Star Coin is here in the upper right corner. Cross to the left side using the yellow platform, then climb up. Near the top, you'll see a set of disappearing stones. Above them is the second Star Coin. It can be difficult to get if the fireballs destroy the stones. Go to the right and you'll see a set of disappearing stones that form stairs. The third Star Coin is in the stairs, between some stones. Time your jump to get it so you can land and escape. The nearby pipe will take you to the flagpole.