Here is the full list of all 31 Zombie Kill of the Week - there are Reborn achievements.
You have wasted 5 hours of your life.
Slaughter 10 000 zombies in total.
Grill 50 zombies with flame in a single match.
Kill 15 zombies with a katana, and 25 with saw in one match.
Slice 53 zombies in one match.
Encounter all 3 tanks, and get them killed.
Slaughter 5000 zombies in total.
Open all areas in a single match.
Fight your way to round 20.
Get a shotgun, and make 20 zombies crawl in front of you.
Own atleast 5000$ in one match
Get yourself killed with a grenade. Dumbass.
Stand still for 30 seconds, wondering about your life.
You have played ZKW for an hour.
Kill the zombie bear before he takes your money.
Help your friend in need.
Get the GiGaGirlGannon, and kill 10 zombies within 10 seconds.
Get promoted to rank 10.
Get 100 headshots in one match.
Zombies are not ment to fly.
Get 5 meats in a single game from the fridge.
Get promoted to rank 30.
And still going?
Go see your friends!
Find the fridge and make it disappear. Repeat 3 times.
Survive 4 minutes in Abandoned Hospital. (Challenge mode)
Survive 4 minutes in RedSnow. (Challenge mode)
Survive 4 minutes in Night At The Mall. (Challenge mode)
Survive 4 minutes in Arise. (Challenge mode)
Survive 4 minutes in Area 73. (Challenge mode)
Survive 4 minutes in Homerun. (Challenge mode)