Highlight the Fun "n" Games option on the fullscreen version of the movie (disc 2) and press enter. Next, HighLight Buddy's Adventure. This will take you to a screen with a Christmas Tree containing four red ornament balls on the left of your screen with four different games to play. 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.
All easter eggs were generously submitted by SirDonk