This source comes as-is. 
It is a complete mess and without any warranties whatsoever.

Main features:
-spawnable monsters
	-spawnable angry monsters
-spawnable items
-items flaggable as secret
-shootable objects may be filtered to only accept damage from specific weapons
-tons of small dumb stuff
-ghosts
-fog controlling volumes

Here are some fun binds to play around with the fog:

bind "b" "impulse 105" //Randomizes all fog parameters
bind "g" "impulse 106" //Resets fog to default
bind "y" "impulse 202" //Increase Red component
bind "h" "impulse 203" //Decrease Red component
bind "u" "impulse 204" //Increase Green component
bind "j" "impulse 205" //Decrease Green component
bind "i" "impulse 206" //Increase Blue component
bind "k" "impulse 207" //Decrease Blue component
bind "o" "impulse 208" //Increase Density component
bind "l" "impulse 209" //Decrease Density component

With these you can 
	-- randomize the fog using b
	-- reset the fog using g
	-- fine tune the color using y/h u/j i/k and o/l to increase/decrease the red, green, blue and density components respectively.