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~~~~~~~~~~~~~~~~~~~~~~~~~~~~3.0 Game Play~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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----------------------3.1 Game Basics (standard blocks)----------------------

Basically you just try to reach the bottom of a deep cave by digging or 
drilling through dozens of block layers.
A single drill usually destroys a single block leaving every block laying on 
top of it open to whatever gravity wants to do with it (let it fall down of 
course, d'oh) but of course it is not always that simple.
There are 4 different kinds of normal blocks (blue, green, red and yellow) 
each with the same characteristics:

- They are destroyed with a single drill.

           X
 ______  __\/___ ______        ______          ______
|red   ||green ||blue  |      |red   |        |blue  |
|      ||      ||      |  --> |      |        |      |
|______||______||______|      |______|   X    |______|

- If they happen to be in mid-air they start shaking for a brief moment 
  before falling straight down.

 ______
|yellow|
|      |
|______|        -->  ______
|red   |  O         |yellow| \O/
|      |<-Y         |      |  Y
|______| / \        |______| / \

- If two or three blocks of the same colour get in contact (no matter if  
  horizontally or vertically) they link to each other creating a bigger  
  block that can't be split up again but is still destroyed with a single 
  drill.

         ______
        |yellow|
        |      |
 ______ |______|           ______________
|yellow||red   |  O       |yellow        |  O       \O/
|      ||      |<-Y   --> |              |<-Y  -->   Y
|______||______| / \      |______________| / \      / \

- If four or more blocks of the same colour (or big blocks equal of 4 
  single blocks) connect they disappear. Should there be a big block  
  consisting of four or more single blocks from the beginning it must fall 
  down at least one row or get in contact with another block of the same 
  colour to disappear.

         ______
        |red   |        
        |      |        
 ______ |______| ______
|red   ||yellow||green |
|      ||      ||      |       
|      ||______||______|                ______________
|      ||green ||red   |  O       -->  |red           |         \O/
|      ||      ||      |<-Y            |              |          Y
|______||      ||______| /_\___        |        ______|         /_\___
|                      ||yellow|       |      ||yellow|        |yellow|
|                      ||      |       |      ||      |        |      |
|______________________||______|       |______||______|        |______|