Preferably 3 or 4 people in the game I have a decent tactic for the pentagon level. I need to do:

"Fire a Pack-a-Punched Ballistic Knife at a downed ally to revive them from a distance."
"In Dead Ops Arcade, use a Speed Boost to blast through 20 or more enemies at one time."
"Shoot at or be shot by an ally with a Pack-a-Punch crossbow and kill six zombies with the explosion."
"Kill the Pentagon thief before it can steal your load-out."

add elmooer and post if you can I'll help you get other ones if you need them.