Impossible cube ambiguity present in a Necker cube illustration, in which a cube is drawn with its edges as line segments, and can be interpreted as being in either of two different three-dimensional orientations. An impossible cube is usually rendered as a Necker cube in which the line segments representing the edges have been replaced by what are apparently solid beams. In Escher's print, the top four joints of the cube, and the upper of the two crossings between its beams, match one of the two interpretations of the Necker cube, while the bottom four joints and the bottom crossing match the
Curiosity: What's Inside the Cube? messages. Players tapped the cubelets to dig through the surface of each layer and reveal the next layer below. The goal was to reach the center and to discover what was inside the cube. Each layer, which had a distinct look or design, contained a clue as to what was in the centre of the cube. Each cubelet destroyed by a player awarded them coins. Coins could be spent on tools that temporarily enhanced the player's abilities, such as picks ranging from iron to steel to diamond that increased the number of cubelets destroyed with each tap, or firecrackers that