When only one pillar is remaining, the power of the sound is increased by 200%. Only those who can destroy the pillars from a far distance can destroy this obstacle completely.
The number of players reduced from 4 to 3 after the fifteenth obstacle. As the game went on, that number fell to 2.
In less than 10 minutes of the game, the number of players fell from 76 to 2. There was still 50 minutes left to go. It showed just how difficult this obstacle course was.
The obstacle course didn't get more difficult as time passed. The obstacles changed, but they all tested the same thing, which was survivability and resourcefulness.
Survivability is the ability to survive regardless of the danger and threats to one's life. It is rare because one would need to have no weakness for them to be able to survive various adverse conditions.