Here is the full list of all 43 Over 9000 Zombies! achievements.
Participate in a multiplayer game.
Kill 900,000+ Zombies!
The army of the undead will march at daybreak!
Construct 1000 Turrets from random scraps of metal!
Kill 90,000+ Zombies!
Construct 100 automated turrets.
Voted the greatest zombie of all time!
Derail the Waltz of the Undead!
Kill over 1000 zombie eyes!
The zombie world is independent of our will.
Kill over 1000 crabs!
Abused patience turns to fury!
Health is the greatest gift, a close second is BRAINS!
Get 30 kills per second!
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."
Collect 100 Power Ups!
Kill over 1000 zombie crows!
Don't call me slow!
Your world didn't end!
Get 15,000 damage per second!
Kill 9,000+ Zombies!
Kill over 1000 zombie dogs!
Zombie Napoleon meets his zombie Waterloo!
You didn't donate your organs...
It didn't taste like chocolate ice cream either...
No 8th symphony for zombie Sibelius!
Not a wimp.
Lots of progress!
You watched the world burn, and survived. It was kind of cool.
Vote for Zombie Thomas Jefferson, or don't.
Green IS good.
Kill 1000+ Zombies!
You won that race.
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!