Boulder Dash's primary feature is that boulders and diamonds are subject to gravity, but the player is not. A stack of rocks and diamonds will roll off of each other into a pile if there is room to do so. A careless player may find himself crushed or trapped beneath a mountain of rubble. Certain enemies, when killed, explode into diamonds which can either be collected or kill enemies or players beneath them. Other enemies simply explode, like highly mobile Exploding Barrels, which can be necessary for blasting a hole in a wall.
Boulder Dash was also a technical achievement, with large, freely-scrolling multi-screen levels potentially filled with falling rubble and roaming enemies. It achieved this effect on relatively underpowered hardware by way of its Invisible Grid; everything moved one "tile" at a time, and enemies were lethal if the player was simply adjacent to them.
This work shows examples of:
- Arcade-Perfect Port: Inverted, as bizarre as that may sound. Boulder Dash was the first game to be ported from a home computer system to the arcade. (There were at least two coin-op versions, Rockford by Mastertronic and Boulder Dash by Data East.)
- Brutal Bonus Level: The V-shaped (and thankfully optional) bonus round, depicted here◊.
- Camera Screw: While the camera tries to keep the player in-view, it's possible to outrun the camera if the speed is high enough. Even without outrunning the camera, you have to be dangerously close to the edge to cause it to pan.
- Eenie, Meenie, Miny Moai: In the NES port, moai heads replace boulders in Ocean World.
- Fan Sequel: Visit sites that offer ROM files of C-64 games and you will find literally hundreds of home-grown Boulder Dash sequels. Megablasters for the Amstrad CPC was also massive.
- Nothing Is Scarier: The only music besides the title theme is heard when the clock is ticking out. Imagine if the last ten seconds were represented by ascending notes, coming in the same number. As one YouTube user commented on the above link (see "Ear Worm"):The "last seconds sound" is still making me pee my pants.
- Remixed Level: Each base layout is remixed five times, with a random sprinkling of boulders and the like. The random sprinkle sometimes forces you to use different tactics, especially in crowded levels. Other levels remain identical, changing only in time or gems needed.
- Selective Gravity: An inversion of most video game examples- Everything is subject to gravity but you.
- Sequel Difficulty Spike: It can be argued that the less-known "Boulder Dash 2", both for the Commodore 64 and designed by Peter Liepa, requires the player to have played the first one before the second, given that the very first level of the second requires the player to blast a hole in a wall by killing a dragonfly (the square-shaped enemy). This game mechanic, alongside the Magic Wall that also shows up in the aforementioned first level, doesn't show up until halfway through the first game, and it's usually exclusive to advanced players (trust us on this one).
- It is All There in the Manual, of course. Then again, not every player had access to the manual.
- Super Not-Drowning Skills: Rockford doesn't seem to have any more trouble than usual breathing in Ocean World in the NES port. In fact, despite appearing to take place underwater, it doesn't play any fundamentally different from the other worlds.
- Tunnel King: Rockford
- Unwinnable by Mistake: Beyond the ability to ruin your own attempt at finishing a level, some levels are unwinnable.
- Boulder Dash Intermission 3 is unwinnable on PAL systems, with the player being spawn-killed. At worst, you don't get the extra life.
- Boulder Dash 3 Cave A-5 is unwinnable, with a boulder blocking the entrance. Caves I-4 and I-5 are also unwinnable. Note that these are checkpoint levels, and you can't complete levels that can only be reached by them.