Adventure · Atari 2600 · 1980
A secret room containing the message "Created by Warren Robinett" — the first Easter egg in video game history.
Atari had a policy of not crediting game developers on cartridges or in documentation, fearing that competitors would poach talent. Warren Robinett, the sole programmer of Adventure, hid his name in a secret room accessible only through a specific series of steps involving a tiny one-pixel dot. Robinett had already left Atari by the time the egg was discovered, making it impossible for the company to remove it before the cartridge shipped in massive quantities. The discovery sparked a company-wide policy change at Atari and inspired virtually every game developer who followed to hide their own secrets in software.
Retrieve the tiny one-pixel Bridge object, located in the black castle area. Carry it to the room with the number 1 dot (through the lower right wall of the gold castle). With the Bridge in the same room as the dot, pick up the dot. Carry both objects past the blue barrier near the eastern wall of the gold castle to reveal a hidden passage leading to the credit room.