Instantly following the Labyrinth's message, lumps of water dropped from the ceiling like cannonballs, plummeting toward the ground and the entrants. No, plummeting wasn't right. The cannonballs of water weren't simply falling. They were shot straight down.
One unlucky entrant didn't catch the message quickly enough. A ball of water struck his head, crushing it.
The splash of blood startled some of the other entrants, and they looked at the mutilated corpse in shock. The rest quickly dodged and turned their heads upward. There was no time limit or any indication of when this would end.
That meant they had to dodge, dodge, and continue dodging.
That was it.
There was no more to it. There were no tricks. No hidden intentions. No requirements. Nothing to keep track of.