Here is the full list of all 43 Over 9000 Zombies! achievements.
Kill 900,000+ Zombies!
Participate in a multiplayer game.
Construct 1000 Turrets from random scraps of metal!
Kill 90,000+ Zombies!
The army of the undead will march at daybreak!
Construct 100 automated turrets.
Get 30 kills per second!
Vote for Zombie Thomas Jefferson, or don't.
Kill over 1000 crabs!
Collect 100 Power Ups!
The zombie world is independent of our will.
Get 15,000 damage per second!
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...
Kill over 1000 zombie eyes!
A jail is an isolated system.
Blood and Flesh can be trusted.
Kill 9,000+ Zombies!
No 8th symphony for zombie Sibelius!
Decreased Zombotropy.
Kill over 1000 zombie dogs!
Zombie Napoleon meets his zombie Waterloo!
Quoth the Raven "Nevermore."
Kill over 1000 zombie crows!
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.
Derail the Waltz of the Undead!
Voted the greatest zombie of all time!
Green IS good.
You won that race.
Kill 1000+ Zombies!
Making some progress...
Get 5,000 damage per second!
The first day is always the hardest, except in this case, it's the easiest.
Construct a turret from scrap metal!
Get 10 kills per second!