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