Boulder Dash

Boulder Dash, originally released in 1984, is a classic series of computer games for the Atari 400/800, Apple II, MSX, ZX Spectrum, Commodore 64, and ColecoVision home computers, and later ported to the NES, Acorn Electron, PC, Amstrad CPC, Amiga and many other platforms. It was created by Peter Liepa and Chris Gray, and on October 28, 1983, acquired and later published by First Star Software, which still owns the rights to the game.

The game's protagonist is called "Rockford". He must dig through caves collecting gems and diamonds and reach the exit within a time limit, while avoiding various types of dangerous creatures as well as obstacles like falling rocks and the constant danger of being crushed or trapped by an avalanche, or killed by an underground explosion. The Commodore 64 version of the first game was also re-released on the Virtual Console in Europe on September 19, 2008 and in North America on June 1, 2009.

Game objects

 * Rockford is the hero of the game, the character controlled by the player. His goal is to collect diamonds and avoid contact with monsters and falling rocks.
 * Dirt and Space are the two basic components of the playfield. Dirt can serve for blocking and/or suspending objects, while space allows them to move freely. Rockford clears dirt as he moves, creating space.
 * Walls are the delimiters of the level. Two basic types exist, destructible (which looks like brick, and can be removed with explosions) and indestructible (made of titanium and from which the edge of the level is usually made).
 * The exit is the final goal Rockford must reach after collecting enough diamonds.
 * Rocks are probably the most commonly encountered elements of the game. Upon removing the dirt from beneath them, they fall until they reach solid ground again. A falling rock can not only crush enemies, but also Rockford as well.
 * Diamonds are the items Rockford must collect in order to open the exit of a level. They otherwise act like boulders.
 * Fireflies are one of the common enemies in the game. When next to a wall, they follow it to their left (clockwise); otherwise they circle around a point in a 2x2 area. When a rock or diamond is dropped on them, they explode in a 3x3 square, destroying anything in that area except indestructible walls and leaving empty space behind. They also explode when Rockford touches them, killing both themselves and Rockford.
 * Butterflies are similar to fireflies, with two important differences. They follow the wall to their right (anti-clockwise) and when they explode, they leave behind nine diamonds arranged in a 3x3 square (unless one of these spaces happens to contain an indestructible wall).
 * Amoeba is one of the most unpredictable elements of the game. It grows at a random rate, by expanding into adjacent space and dirt. The level settings include a duration after which the amoeba's growth rate will dramatically increase. The amoeba is not directly dangerous to Rockford, although it is capable of enclosing and trapping him, or blocking him from reaching the exit. If the amoeba grows too large, it will solidify into boulders, and if it is stopped from growing any more, it will crystallize into diamonds.
 * Slime looks similar to the amoeba (colored blue instead of green), but it works completely differently. Slime does not grow, and does not cause enemies to explode on contact. Its functionality is revealed when dropping a rock or a diamond on top of it; slime has a permeability rate which defines how long the item will remain sitting on top of it before falling through. This happens in quite a sudden and random manner, making the game rely on improvising even more.
 * Expanding walls look and act just like destructible walls, with one difference: when possible, they expand horizontally, often trapping the player or enemies. Expanding walls are made out of themselves - blowing a hole in the middle of a row causes it to close in again almost immediately.
 * Magic Walls look and act just like destructible walls except that when a boulder is dropped on a magic wall, it falls through and turns into a diamond. Conversely a diamond dropped on a magic wall turns into a boulder.

Boulder Dash series
The official Boulder Dash games started in 1984 with the original home computer title, and continue to be published by First Star.
 * Boulder Dash (1984) – The original Boulder Dash was published on multiple home computer and consoles.
 * Boulder Dash (1984) – It was then released on arcade console by Exidy. This version was almost identical, but with coins buying 30 seconds of game time. Historically, this was the first home computer title to be converted to an arcade console.
 * Boulder Dash (1985 – Arcade) – In 1985 Comptiq released another arcade version on Data East's "DECO Cassette System", with improved graphics but a reduced display grid on a vertical monitor.
 * Boulder Dash II (1985) – The second home format was published under several different titles; Rockford's Riot on the MSX, Rockford's Revenge on the C64 (with the former used with the ZX Spectrum's marketing, but the latter used on the cassette inlay), whilst in Japanese it was titled Champion Boulder Dash.
 * Boulder Dash 3 (1986 – Apple II, C64, Spectrum, PC) – Monochrome space-themed graphics and poorly designed levels made this a critical failure.
 * Boulder Dash Construction Kit (1986 – Apple II, C64, Spectrum, Atari 800, Atari ST) – This release included a small number of levels, but was titled Boulder Dash IV – The Game for the Spectrum re-release.
 * Rockford (1988 – Arcade, Amiga, Atari ST, Arcade, Spectrum, Amstrad, C64) - Rockford was originally a licensed arcade game produced by Arcadia Systems, and later converted to various home computer formats
 * Boulder Dash Part 2 (1990 – Arcade)
 * Boulder Dash (1990 - Game Boy)
 * Boulder Dash (1990 - NES)
 * Boulder Dash Ex (2002 – Game Boy Advance) - This one has a new "EX mode" and "Classic mode" which is a direct port of the 1984 PC version.
 * Boulder Dash Xmas 2002 Edition (2002 – PC)
 * GemJam Gold (2003 – PC) – The game's credits claim this is based on Boulder Dash, and is licensed by First Star.
 * Boulder Dash – Treasure Pleasure (2003 – PC)
 * Boulder Dash: Rocks! (2007 – PSP, DS)
 * Boulder DAs Vol 1'(2009 – iPhone OS)

Reception
Mean Machines gave the Game Boy port of Boulder Dash a score of 90%, praising it as "one of the finest video games ever written", describing the game as "one to buy as soon as possible" and noting its faithfulness to the original Commodore 64 version.