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