Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Arthur	Find your father.
Hourglass	Obtain the Hourglass.
One of many	Obtain the first crystal.
Prophecy	Solve all puzzles.
Secret cave	Deep under the pyramid.
The Crocodile	Insert the second seal.
The Scarab	Insert the first seal.
The Snake	Insert the last seal and open the gate.
The fifth crystal	You could need this one...
Your journey begins	Path to the first seal.