About: Inspired by the abandoned Skulltag game mode of the same name. The goal is to kill all the monsters in the level in order to exit, rather than just rushing through the level and flipping the switch.
Protip: Pain Elementals are even more annoying than usual!
Compatibility: Skulltag, most likely ZDoom and others. Does NOT work with new monsters unless you modify it yourself. (Pretty trivial to do if you are the slightest bit familiar with DECORATE.)