Now, enter the Tower of Druaga exhibit halls. Go directly forward untill you bump into a wall. Pac-Man will indicate there's something there. Press X and he'll dig through the wall. You'll see a 3-D battle between Gil and Druaga, and a new Tower of Druaga to play.
Start a game, and although the diagrams of the tracks look normal, they have drastically changed! (Check out the Test track!)