The mole Jerry has a problem, his home is about to be crushed by a huge amount
of gems, which moving toward him.

You are playing Jerry and your job is to prevent this event, the crushed home.

Your job is to create a row of 3 gems of the same kind. To do so, you first
collect gems, by standing beneath a certain gem, then you can catch this (or
these) gem(s). You will catch all gems of the same kind which are vertically
adjacent, so if there is one, you catch one, if there are five, you catch
five. Once you have a certain gem type in your hands, you can now either throw
them back, to create a 3 gems row, or you can catch other gems of the same
kind, before you throw them all back.

If you attach those gems to a bulk of gems, you can remove dozens of gems once
you created a 3 kind row. Gems which were below those gems, which are removed
now, will fall back to attach to the others.

A level consists of a playfield, which has at the beginning 7 rows with 9 gems
each. The longer you take in a level, the more rows appear on the playfield.
Once there are 10 rows, you only have a few seconds to get rid of the 10th
row, or the game ends. The rows are increasing simply because each level has a
pre-defined amount of gems, i.e. 120 for the first level, so 14 rows are
possible.

From level to level, the gem dropping speed will increase. So, at the
beginning you have plenty of time for thinking, but later, you better think
fast.

But not only the level speed increases over the levels, but also the amount of
power-ups and obstacles available.

Obstacles are coal, rock, and slime. Once you caught a gem, which is beneath a
rock, the rock will fall down. If you standing in the way, you are knocked out
some seconds. If you don’t stand in the way, the rock will just smash and is
gone then. This also applies to the slime bottle, but, when the bottle is
smashed, the slime will be some time at the ground and the ground will become
slippery. Coal is a blocker, it won’t fall down, except you catch it. It will
smash if you throw it back.

Power-ups are the Stonelifter, which will lift all gems some rows up. The
Bomb, once thrown up, it will explode and destroy some adjacent gems. And the
Rifle, which will destroy all gems in two adjacent vertical rows.

Finally, there are two special gems, the Magic Stone, which will remove all
same colored gems, even not adjacent ones, once it is used in one of the 3
gems rows. And the Diamond, which will change the type of many adjacent gems
in the type of gems, which it is attached to.