Here is the full list of all 43 Over 9000 Zombies! achievements.
Voted the greatest zombie of all time!
Get 30 kills per second!
Kill over 1000 crabs!
Zombie Napoleon meets his zombie Waterloo!
The army of the undead will march at daybreak!
Construct 100 automated turrets.
Kill over 1000 zombie crows!
Kill over 1000 zombie eyes!
Collect 100 Power Ups!
Vote for Zombie Thomas Jefferson, or don't.
Derail the Waltz of the Undead!
No 8th symphony for zombie Sibelius!
Kill over 1000 zombie dogs!
Get 15,000 damage per second!
Kill 9,000+ Zombies!
The zombie world is independent of our will.
Abused patience turns to fury!
Health is the greatest gift, a close second is BRAINS!
Terror possessed me then!
If only he had the body of a horse...
A jail is an isolated system.
Blood and Flesh can be trusted.
Decreased Zombotropy.
Quoth the Raven "Nevermore."
Don't call me slow!
Your world didn't end!
You didn't donate your organs...
It didn't taste like chocolate ice cream either...
Not a wimp.
Lots of progress!
You watched the world burn, and survived. It was kind of cool.
Green IS good.
Kill 1000+ Zombies!
You won that race.
Get 5,000 damage per second!
Making some progress...
Construct a turret from scrap metal!
The first day is always the hardest, except in this case, it's the easiest.
Get 10 kills per second!
Participate in a multiplayer game.
Kill 90,000+ Zombies!
Kill 900,000+ Zombies!
Construct 1000 Turrets from random scraps of metal!