Select Buddy's Adventure. You'll be taken to a screen with a Chritmas Tree that has 4 ornaments. You can select all 4 ornaments to play mini-games. If you win every game you'll get a code.
Select the arrow to the right of the screen (on the easel). Enter the code for the Secret Elevator O Fun.
The code... Incase you don't want to play 4 mini games is 1225
On the right side of the screen you will see an easel with an arrow on it. Highlight the arrow and press enter. This will take you to a numeric keypad. You need four numbers to gain access into the elevator. You can obtain the numbers by successfully playing all four games on Buddy's Adventure. This means you cannot hit any obstacles while playing the game, even if the game says you won. This is very frustrating, but I did it. Here are the four digits, just in case you need them. Remember highlight the arrow on the easel and then type in the numbers "1225." Good luck with the games