[An emulator

Bouldercraft is a survival-oriented world simulation game based on a 2D cellular automaton. It is basically a clone of Boulder Dash with some characteristics of Minecraft (hence the name). The game was completely created by Viznut in October 2022 and the first version (0.2) was released at the Zoo demoparty.

The game is still at an early stage of development, so the game logic is still subject to change. This document describes the game as of version 0.4.

At the moment, Bouldercraft is only available for the Commodore 64, but versions for other platforms are likely in the future. The main game logic is written in C, so modifying the logic and porting the game into non-6502 platforms will hopefully be easy. The source code will be released on Github once a minimum level of maturity is reached. The licence will be chosen at that time.


bouldercraft.prg (version 0.4 for the Commodore 64 and emulators such as VICE; size 8123 bytes -- yes, this html page is larger)


Long-term survival is the essence of Bouldercraft. The longer you stay alive, the more you score.

Staying alive consumes energy, and you need to eat to gain it. The energy capacity peaks at 999, so you will need to consider when and how to eat. If there's plenty of food available, you may want to conserve the food in order to prevent it from rotting away.

The world is not reset between lives, so you can reincarnate into it and use whatever you managed to create earlier. Spending several lifetimes building a bunker and securing a reliable and manageable food source is a strategy that may get you into high scores.

Moves and actions

Bouldercraft is designed to be played with a controller that has four directions and a single button ("fire"). What the player character does depends on what lies in the moving direction and whether the button is pressed.

When moving towards a direction without pressing the button:

When moving towards a direction while pressing the fire button, the player character stays in its place while doing something to the cell in the direction:

A dead player may only select the horizontal position for the next incarnation (by moving left and right) and incarnate (by pressing the button).

The world

The world consists of a grid of 64 × 14 cells, each containing a single element.

Some element types have subtypes depending on the state (a rock can be either falling or stationary, and there are four subtypes for the eater depending on the direction it's currently moving to). These state differences can mostly be ignored by the player, so they won't be covered there.

There are slow and fast natural processes in the game. Fast processes (such as the falling of rocks) apply to the entire world several times per second, while slow processes (such as the growth of plants) only apply to a single column of cells at a time. This column is marked by the Sun. Some processes only take place in the topmost non-air column under the Sun (the vaporization of water, the rotting of mushrooms, etc.)

Slow processes are caused by the Sun that continuously passes over the world. When the Sun has reached its rightmost position and reappears on the left, certain balancing operations take place in the form of items that will be randomly created on the top of the world:


Air Family:

Water Family:

Fire Family:

Earth Family:

Rock Family:

Plant Family:

Animal Family:

Artifact Family:

These do not appear naturally but require the player to craft them.