Adventure

Adventure is a 1979 video game for the Atari 2600 video game console and is considered the first action-adventure game. Its creator, Warren Robinett, also introduced the first widely known Easter egg to the gaming world.

Adventure was published by the console's developer, Atari, Inc. It was inspired by a computer text game, Colossal Cave Adventure, created by Will Crowther and later modified by Don Woods.

Despite discouragement from his boss at Atari who said it could not be done, game designer Warren Robinett created a graphic game loosely based on the text game. Atari's Adventure went on to sell a million copies.

At the time of the game's creation Atari did not credit any of its authors for their work.[5] Robinett included a hidden message in the game identifying himself as the creator,[4] thus creating one of the earliest known Easter eggs in a video game. According to Warren, a young player from Salt Lake City, Utah first discovered the easter egg and wrote in to Atari regarding it.[5]

The total memory used by the game program was 4096 bytes (4 KB) for the game code (in ROM) and 128 bytes for program variables (in RAM). The Atari 2600's CPU was a 1.19 megahertz 8-bit MOS Technology 6507, which was a cheaper version of the 6502.

Due to a limitation in the Atari 2600's hardware, the left and right sides of nearly every screen are mirror images of each other, which fostered the creation of the game's confusing mazes. The notable exceptions are two screens in the black castle catacombs and two in the main hallway beneath the Gold Castle. These two hallway screens are mirrored, but contain a vertical "wall" object in the room in order to achieve a non-symmetrical shape, as well as act as a secret door for an Easter egg.