Casino Delfino is a location in Super Mario Sunshine. It is one of the accommodations offered at Hotel Delfino. While it is occasionally the focus of an episode, it is otherwise entirely inaccessible. To enter it when it is available, Mario must speak with the Pianta guarding the door to the casino in the hotel lobby. While in the casino, Mario may pick up a few coins and access a hidden bonus area.
It is to be noted that once the casino is entered, Mario may not return to other areas of the hotel without exiting the level.
Although Yoshi cannot be brought into the casino under any circumstances, a version of the casino theme with the added bongos exists in the game's files.
In The Manta Storm, the entire hotel is inaccessible.
With The Hotel Lobby's Secret, though the hotel may and must be entered, the casino cannot be accessed due to not contributing to the focus of this episode.
In Mysterious Hotel Delfino, the casino is once again inaccessible, being one of the few areas of the hotel not visited during this episode.
As for The Secret of Casino Delfino, the casino is accessed as well as the main focus for this episode. Mario must enter the casino via the lobby and score triple sevens on both slot machines on opposite ends of the casino. Doing this opens up the curtain in back to reveal a puzzle with tiles Mario must rotate to complete the image of a Shine Sprite, which in turn opens up a Warp Pipe leading to the bonus area.
In King Boo Down Below, though the casino is closed due to paranormal activity below it, it remains the focus of this episode. Mario must enter the casino to find it is now empty, and there is a conspicuous purple tile on the large roulette wheel in the center of the casino. He must Ground Pound this space to lower the wheel into the arena where King Boo is fought.
From Scrubbing Sirena Beach onward, the casino is not accessible in any of the episodes until Red Coin Winnings in the Casino, though the mission plays exactly like the previous episode with the exception of added Red Coins in the bonus area accessed via the casino.
The casino is located on the west side of the hotel, separated from the lobby. Mario must speak to the Pianta guarding the door to the casino to enter it, at which point he may not leave. If the casino cannot be accessed during that mission, he is not allowed entry. In the center of the casino is a large roulette wheel of red and green tiles. This concept comes into play during the fifth mission, in which one of the tiles becomes purple as a clue for what to do. On the east and west sides of the casino, there are slot machines of three depicting images of Boos, coins, coins in sets of three, and sevens. One of the slot machines tilts the images separately while the other spins them together, though both are played with water.
In the corners of the casino are smaller machines for gambling. Mario may Ground Pound the tops of the machines for some coins. In the back of the casino is a curtain which is pulled up once the slot machines have been cleared. After Mario completes the tile puzzle behind the curtain, the pipe leading to the secret area is revealed. While the casino is normally occupied by Nokis and Piantas, during the fifth mission, it is empty. Also during this mission, Mario may locate a large piece of graffiti above the door designed for exiting the casino, which he may water down to receive a Blue Coin.