Puzzle Rules - Digging carefully

Fantasy and Gameplay

You're an archeologist carefully removing dirt to discover an ancient Artefact.

• The tool damage the artefact but is needed to remove the soil.
• When removing soil, if an artefact is behind, the tool damage it.
• Player has to find a way to remove the soil without destroying the artefact.

Rules

• Fragment hit point
• Fragment have [4] hit points (FHP)
• when FHP reach 0, the fragment is destroyed ; player didn't succeed the puzzle

• Digging Effect
• Tap to remove a soil cube
• Removing a soil cube has an effect on the cube behind it.
• The face hit determined which cube behind receive the effect.

• Cubes types and digging effects

• Hard Soil
• hard soil has 2 Hit points 
• when its hit points reach 0, it is removed. 
• Rock
• Rocks are special 'blocking' ingredients ; player needs to carefully remove them.
• Shake: when a rock shake, it damages surrounding fragment; - 1 FHP if any of the 6 orthogonal neighbours is a fragment.
• Rocks are automatically removed when they have only 1 neighbour (later we could add a hold and slide control so player remove it himself).

Dynamics

Consider the following 2D puzzle made of soil, fragment and hard soil.

• Situation A
• player has 2 good choices (green dot) and 1 bad choice (red dot)
• player has be careful of "what's behind"; maybe it's a fragment and it would be damaged. We could use this lack of information (what is behind?) as a difficulty parameter. Player would have to make hypothesis and search ways to confirm them.
• Situation B
• To remove the Hard Soil, player has to damage it 2 times. If player dig the wrong soil direction (red dot inside the circle) he won't be able to remove the hard soil.
• Depending on player choice, he might not be able to remove all Cubes, and so don't succeed the puzzle.