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