Over the Rainbows

Wing Mario Over the Rainbow is a secret level in Super Mario 64 and Super Mario 64 DS, though it is renamed Over the Rainbows in the latter. The entrance to the course is through a hole with light coming out of it on a ledge to the left of Tick Tock Clock, opposite of the entrance to Rainbow Ride.

Layout
The platforms around this course are clouds that Mario has to fly between using the Wing Cap or by using cannons. If the player falls to the abyss below, they will be dropped into the lake in front of the castle with no life lost. To open up the cannons, the player needs to make it to a large, pink platform with the Bob-omb Buddy and talk to him. Two of the clouds are transparent and Mario can fly right through them, one contains a Red Coin and the other contains a 1-Up Mushroom. One other cloud has a group of green poles hanging down from it. In Super Mario 64 DS, the course went through a few changes: two trees and a Black Brick have been added, and the Red Coin that was on one of the transparent clouds was moved to the regular cloud located under the group of green poles.

Missions
This course has two Power Stars to collect, one of which is exclusive to the DS version.

Red Coins
Using the Wing Cap and cannons, Mario must fly around the level and collect the eight Red Coins to make a Power Star appear at the Star Marker on the cloud the player started on.

Black Brick (DS only)
A Black Brick can be found on one of the clouds. If Wario can get to the block (either by long jumping or use of a cannon), he can break it to earn a Power Star.

Trivia

 * This is the only secret course that utilizes cannons.