World

Each world is 16,384 blocks in circumference and 1024 blocks from magma to space. Sea level is 512 blocks from space and 512 blocks from magma. It has biomes, climate zones, poles, an equator, and celestial objects can be seen especially in the clear night sky.

Structure

Although The Blockheads is mostly two-dimensional (left-right and up-down), a certain amount of "depth" is visible. The effect is as if there are four layers of depth:

Foreground - Where solid and liquid blocks and Blockheads exist. A Blockhead can move through liquid blocks (air and water), but not solid ones.
Mid-ground - Where most objects that a Blockhead can move past exist. Blocks in the foreground have a presence here as well.
Background - Where any "back wall" blocks or objects exist. A block that's only in the background can be acted on to have a mid-ground object placed on it. Most foreground blocks have a presence in the background behind it and all non-solid blocks below it until interrupted by another solid block.
Sky - Where celestial objects exist.

Bedrock

Below a certain point, the default background layer ceases to be air and becomes stone, preventing any other block from displacing it. This background is present even if no solid blocks are anywhere above it, and usually is initially created where the overlying layers of dirt and sand stop and underlying stone begins. As such, this can be called the world's "bedrock."

Display

The visible world can be displayed at any of three scales. They can be changed between by two-finger sweeps (pinching and spreading).

Default - Blocks are displayed at the same size as the inventory icons on the right of the display.
Small - Blocks are tiny, allowing more of the world to be viewed at one time.
Large - Blocks are large, allowing more detail to be seen and tapping to be more accurate.

The exact amount of a world that can be seen at one time depends on the device and scale used.

Display Dimensions in Blocks
	Default	Small	Large
iPad 1	19x26	38x52	9.5x13
iPhone 5	8x13	24x39	4x7

Known World

Only those areas seen previously are visible. Any changes are also visible, even if a Blockhead is not near the area being viewed.