Boulder Dash

Boulder Dash is a maze-based puzzle video game released in 1984 by First Star Software for Atari 8-bit computers. It was created by Canadian developers Peter Liepa and Chris Gray. The player controls Rockford, who tunnels through dirt to collect diamonds. Boulders and other objects remain fixed until the dirt beneath them is removed, then they fall and become a hazard. Puzzles are designed around collecting diamonds without being crushed and exploiting the interactions between objects (such as a butterfly turning into diamonds when hit with a falling rock). The game's name is a pun on balderdash.

Boulder Dash was ported to many 8-bit and 16-bit systems and turned into a coin-operated arcade video game. It was followed by multiple sequels and re-releases. Many games were influenced by Boulder Dash, such as Repton and direct clones like Emerald Mine, resulting in the sub-genre of rocks-and-diamonds games.

Boulder Dash takes place in a series of caves, each of which is laid out as rectangular grid of blocks. The player guides the player character, Rockford, with a joystick or arrow keys. In each cave, Rockford has to collect a set number of diamonds within a time limit. Player has to avoid falling rocks and other obstacles, including amoeba, butterflies, and fireflies. When enough diamonds have been collected, the exit door opens, and going through this exit door completes the cave.

As an aspiring game developer, Peter Liepa reached out to a local publisher called Inhome Software. They put him in touch with a young man—Chris Gray—who had submitted a game programmed in BASIC that was not commercial quality, but had potential. The project began with the intention of converting this game to machine language and releasing it through Inhome, but according to Liepa, the game was very primitive. He decided to expand the concept and add more interesting dynamics, and he wrote the new version in Forth in about six months. When it became clear that the game was worth releasing, Liepa rewrote Boulder Dash in 6502 assembly language. Dissatisfied with the lack of a contact from Inhome Software, Liepa searched for a new publisher. He settled on First Star Software, which, according to him, was very happy to publish the game.

The game was licensed by Exidy for use with their Max-A-Flex arcade cabinet. Released in 1984, it allows buying 30 seconds of game time. This was the first home computer game to be converted to an arcade console.