Nintendo Entertainment System Boulder Dash USA
0Game objects
Rockford, left, drops a series of boulders on a series of butterflies. The butterflies explode into diamonds, which fall down the shafts. Commodore 64 version.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. It is disguised as an indestructible wall, and reveals itself after the required number of diamonds is collected.
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. Rocks can also "roll off" of other rocks and destructible walls if there is space beside them, and Rockford can also push single rocks sideways if there is nothing else in the way.
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. The second advantage that Rockford can exploit from the amoeba is that both fireflies and butterflies will explode on contact with it, the latter being the most advantageous.
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. If there is no empty space underneath the magic wall, a boulder or diamond dropped onto it will simply disappear. The level settings specify the amount of time that magic walls will "mill", i.e. turn rocks into diamonds and vice versa; after which they deactivate, and any more rocks or diamonds that fall onto them will simply disappear.
SeriesThe official Boulder Dash games started in 1984 with the original home computer title, and continue to be published by First Star.