Here is the full list of all 43 Over 9000 Zombies! achievements.
The zombie world is independent of our will.
Abused patience turns to fury!
Kill over 1000 crabs!
Get 30 kills per second!
Collect 100 Power Ups!
Kill over 1000 zombie crows!
Zombie Napoleon meets his zombie Waterloo!
Kill over 1000 zombie dogs!
Voted the greatest zombie of all time!
Health is the greatest gift, a close second is BRAINS!
Terror possessed me then!
No 8th symphony for zombie Sibelius!
If only he had the body of a horse...
A jail is an isolated system.
Blood and Flesh can be trusted.
Decreased Zombotropy.
Kill 9,000+ Zombies!
Quoth the Raven "Nevermore."
Don't call me slow!
Get 15,000 damage per second!
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.
You won that race.
Kill 1000+ Zombies!
Construct a turret from scrap metal!
Making some progress...
Get 5,000 damage per second!
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!
Vote for Zombie Thomas Jefferson, or don't.
Construct 100 automated turrets.
Construct 1000 Turrets from random scraps of metal!
Kill over 1000 zombie eyes!
Derail the Waltz of the Undead!
The army of the undead will march at daybreak!