They appear when the player has more than 25% Enlightenment. Above 50% Enlightenment, they no longer try to avoid the player and will attack if the player is in range. Above 80% Enlightenment, they will follow and attack the player if they are within less than 1.5 tiles.
When approached, they will ball up and shoot in the player's direction. This can be avoided by moving out of the way. Their attacks deal no damage, and will instead increase Enlightenment by 10 and slow down the player for a few seconds. If the player is hit by too many Gestalt in a row, they will fall asleep for 6 seconds.
Gestalt is a German and Swedish word for "figure" or "form". It is also a psychological term used to describe perceiving order in a chaotic world, usually by grouping objects together or connecting them.