SECRET CITY: Atari 2600 VCS
Select game 2 or 3 and enter the maze in the Black Castle. Move to the screen to the left of the first maze screen. At the bottom center of this room is a closed cubicle. Use the bridge to enter that area and collect the "dot". Carry this item to the screen just above the catacombs, located one screen down and to the right of the Gold Castle. Note: The "dot" is the same color as the ground outside, so care must be taken not to lose it in transit. Drop the "dot" here, and bring two other items onto the same screen. Move through the line on the right side of the screen to view the programmer credits.
Enter the escape tunnel and quickly go up and down in the tunnel a few times without coming out. Go down as your last move and Pac-Man will "wipe" into the screen. He can now move up and down in this vertical plane through the walls, but not sideways.
Eat a single ghost on maze 1, eat two ghosts on maze 2, three ghosts on maze 3, and four ghosts on maze 4. Then, press Up, Down, Up and intentionally lose a life.
Twice the shot:
Hold down the RESET button when you power up the system to enable the double shot feature.