The Talos Principle underwent 15,000 hours of playtesting — but not by humans (interview)

In Croteam’s new philosophical puzzle-adventure title, it apparently takes a robot to fully test one in-game.

The developers of the Serious Sam shooter series have turned their talents to The Talos Principle, a game that puts you in the metal body of a robot with a seemingly human consciousness, attempting to determine your role and the fate of the human race.