This room is found in the Toxic Spire of the Sky Dominion. The entrance is found at the very top of the spire by the level's exit, within a fountain that can be entered after hitting a series of switches. Unlike other treasure rooms where the player navigates through a maze to find coins, the path through this room is very linear with the player being carried on a cloud along a trail of coins. Though the player can move forward, they cannot move back to retrieve coins they may have missed. Because of this limitation, Cloud 9 is considered to be one of the more difficult Treasure Rooms in the game. Also it's not easy to see where a player needs to be standing on the platform to grab each coin as it floats by since the platform moves somewhat erratically.
Only 1-4 coins (depending on the amount of players) can be obtained on a whim, that's on the solid platform in-between parts. This room is divided into two parts; a heavenly, peaceful side, and a Hellish, demonic side.
On this side, the skies are blue, and the clouds are white and fluffy. A warping rainbow sits beneath the path of the cloud, and the beautiful gates to the Hellish side are seen ahead of the player.
Once the player passes over a platform between the gates, the scenery changes abruptly. On this side, the skies are dark red, and the clouds are orange and fiery. Only the Deathly gates to the Heavenly Side are seen behind the hero in this part (aside from the coins).