I fine-combed the map Unrest Procedure of our first-place winner after Easter eggs and bugs, this is what I found. If you press this button next to the three boxes ten times the door will shatter, Revealing a panel. When the panel is pressed it opens a Combine door where you battled the hunters. Inside is a freaky-looking room go check it out for yourselves.
Is EEs and bugs "The Arena"
IDN I can only fine-combe one map at a time