Super Mario World/Donut Plains 1

Donut Plains 1 is the first stage of Donut Plains. The Cape Feather makes its first appearance in this level. At first, Super Koopas will come flying towards Mario, the first one will leave a Feather if you stomp on it. The first bush after those Koopas hides a mushroom, walk past it and it will pop out. To find the key you must go the Information block that's after the green pipe. If you have turned on the Green Switch, you can run up the Green Block wall using the Triangle Block. If not, you would have to fly up to where the key is placed, which can be more difficult, since there are a lot of obstacles.