The first Star Coin is above some bricks over a giant skeleton koopa. Break the bricks and jump off the giant koopa to the Star Coin.

In between 2 giant spikes is a pipe on the bottom hidden by the clouds. Jump from the right to get to the pipe. It’s right below the background stone arch. Fall straight down or you’ll be hit by 2 spikes. The Star Coin is in the upper right.

The flag is hidden in the clouds above a ?-block. it’s just to the right of 3 small spikes where you have to crouch on the sign.

There is a hidden powerup to the far left of the door. Ludwig himself can be a beast because of these 3 rising and lowering platforms. Try to be on the high side when Ludwig jumps so by the time he comes down it will be on the low side. 3 times to win. Will be a lot easier with a Propeller Suit.