Captain Toad finds himself near two tall towers high in the sky. Step on the green switch to make green flip panels appear. Follow them to reach the lower part of the tower with the Star. Collect the invisible coins there. Hit the next switch to make a path to the other tower. On the way, you'll pass some donut lifts. Collect the coins and the first gem. There are two switches by this tower. Hit the left one so you can reach the ladder on one side. Climb up and you'll find some plants. One has the second gem. Drop down on the side with the switches and wait for the switch to reset. Hit it again and walk to the side opposite the ladder. Use the ladder to get the coins on the inside of the tower and drop back down to the switches. This time, hit both switches. You'll want to hit the switch on the right a little earlier than the one on the left. Follow the path of the right switch to the donut lifts with the third gem. This will allow you to reach the left switch's path, which will move faster. Follow it up to the part of the tower with the Star. There are some coins along the outside edge of the tower you can collect.
Special Challenge: Collect 45 coins.