Select game 2 or 3 and enter the maze in the Black Castle. Move 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.
Slow End Music
Press Select immediately after ending the game to hear the ending music played very slowly.
Walk Over Title Screen
Start game play, then press Select to view the game selection screen, with the game number displayed in the center. Press Down to have your character appear and move over this screen.
Mr. Robinett's Message
Start Game Variation 2 or 3. Enter the Black Castle. Make sure you have the Bridge handy. Make your way through the maze until you get to a screen where everything begins to flash. As we know by the limited amount of objects available on screen at once, this can only mean one thing: there is something else in this room.
Using the Bridge, enter a small square room at the bottom center of your screen. This room contains a small "dot" that is only 1 pixel in size (by comparison, your character is 16 pixels in size; four wide and four deep). The dot is not invisible; rather, it is the same color as the ground. If you want to make sure you have it, simply walk near a wall on the side you're carrying it. It should show up.
Take the dot to the room just below and to the right of the Yellow Castle. This is the room with a black band running up and down the right side. Drop the dot somewhere in the room. Go and get two more objects and drop them in this room. The black line should flash. Simply walk through the line and enjoy a little piece of history!
Walking Through Walls
The Bridge can be a fun little time waster. Experiment a bit with it; it is possible to use it to travel to screens you shouldn't be allowed to travel to!