Earn a grade of 'B' or higher on the 'Eagle Eye Engagement' Challenge.
Kill a Winged Horror for the first time in Survivor mode
Earn a grade of 'S' or higher on the 'Stone Age Struggle' Challenge.
Kill a Cheerleader for the first time in Survivor mode
Kill a Flesh Beast for the first time in Survivor mode
Earn a grade of 'A' or higher on the 'Aerial Assault' Challenge.
Earn the shotgun for the first time in Survivor mode
Earn a grade of 'B' or higher on the 'Poor Equipment' Challenge.
Earn a grade of 'A' or higher on the 'Napalm Warfare' Challenge.
Kill 100 Zombies in one game in Survivor mode
Kill 200 Zombies in one game in Survivor mode
Earn a grade of 'B' or higher on the 'Engineer Prodigy' Challenge.
Earn a grade of 'B' or higher on the 'High Tech Horror' Challenge.
Earn a grade of 'S' or higher on the 'Tougher Than Nails' Challenge.
Earn a grade of 'A' or higher on the 'Unstable Ground' Challenge.
Earn a grade of 'B' or higher on the 'Undead Attrition' Challenge.
Earn a grade of 'A' or higher on the 'Close Combat Clash' Challenge.
Earn a grade of 'B' or higher on the 'Living Nightmare' Challenge.
Kill a Skinny for the first time in Survival mode
Kill a Hound for the first time in Survivor mode
