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