When you get here, Birdie will tell you that Hamburglar has fled to Grimace's Highlands. If you give her at least five cards of her puzzle, she will show you the way.
Level 1 - The Stratosphere
Walking on clouds can be a little difficult at first, as the clouds partially hide your character and enemies. You will immediately notice a card above you. To get it, jump to the moving cloud on the right and then to the clouds in the upper left. This way, you can easily land next to the card and grab it. Then continue to the right. Using other moving clouds you can reach a good number of arches and another card. Further to the right, jump on the fast moving clouds to reach a zipper surrounded by blocks on the left. Upon entering, you will find yourself on a row of blocks with two 1-Ups, which you have certainly already noticed. Take the extra lives and climb the fast moving clouds again. This time up, jump to the right. Take the arches on the cloud and take a long jump to the right, to land on a ledge with another zipper. Enter to access a bonus level. In this level, use the moving clouds to take several arcs and two 1-Ups. You will also discover that in some places you can also walk inside the clouds. Enter the zipper at the end to return to the main level. Let yourself fall, but stay against the cloud on the right. You will land to the right of the finish line.
The first card you found is for Birdie's Treehouse and the second for Hamburglar's Hideout.
Level 2 - Slippery Slopes
In this level the ground is frozen and slippery, so you have to move carefully. You will also have the ability to collect snowballs from the heaps, to throw them at enemies. Continue to the right, climb the frozen platforms and take a long jump to the left. You will come to a platform with a spinner, use it to flip over. On the left you will find a super springboard with a block next to it. Use the block and the super springboard to reach the 1-Up you saw at the beginning of the level. Then go back to the spinner and straighten up. To the right of the platforms you crossed earlier there is a springboard, use it to reach a platform at the top right. At the end you will find a card. Go down. Be careful while walking on the snow bridges, because if you jump on them, they will collapse. Under the short snow bridges you will encounter, there is 1-Up at the bottom right. Grab it, but be careful not to fall. After having climbed other snow bridges, continue to the left, there is a zipper above some blocks. Enter to reach a bonus level. In this level you will have to go down using the lifts and collecting the arches. When you notice a tree trunk, jump to its left. Here you will also find two 1-Ups. Then use the super springboard to go back upstairs and reach the zipper on the right, which will take you back to the main level. Here you grab a block and make your way to the super springboard to the left of the finish line. You can then take a big jump, reach a platform with arches at the top and go to the right of the finish line.
The card you found is for Birdie’s Treehouse.