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The System Purge, also called just the Purge or the Carnage, was when Marty Mikalski and Dana Polk unleashed all the monsters in the glass rooms into The Facility. This was accomplished with a button in the control panel marked "System Purge." During the Purge, each and every one of The Facilities monsters are let out in waves, eight at a time. The first wave of monsters includes: the werewolf, the zombies, a witch, the Dismemberment Goblins, the dragonbat, the Giant Snake, the Angry Molesting Tree and the killer robot.
Why the facility had the need for a System Purge is unknown, but it is likely that this is a reference to the eleventh-hour deus ex machina that is a common trope in the horror genre.
Assim, o botão é uma sátira óbvia do "deus ex machina", de décima primeira hora, em filmes de terror. (Referência)