Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Bathing is lame	Chapter 1, Level 4, don't drown a single zombie.
Beginning of the end	Finish Chapter 1, Level 1.
Caring neighbour	Lvl 5, explode all racers.
Expired fish food	Drown 200 zombies.
Horde	Reach 120 zombies alive.
Is this easy mode?	Chapter 1, Level 6, dont use the Ressource Extractors that appear mid-waves.
Jumping ships	Finish Chapter 1, Level 4.
Legion	Reach 150 zombies alive.
My precious	Finish Chapter 1, Level 3.
No brain no helmet	Finish Chapter 1, Level 6.
No president of mine	Finish Chapter 1, Level 2.
Red neck lover	Lvl 5, dont kill a single red neck.
Sh*t does not float	Drown 50 humans.
SnowBall - Chapter 1, Level 1	Finish level having spawned less than 11 Biter zombies (starter zombies count)
SnowBall - Chapter 1, Level 2	Finish level having spawned less than 50 Biter zombies (starter zombies count)
SnowBall - Chapter 1, Level 5	Finish level having spawned less than 10 Biter zombies (starter zombies count)
SnowBall - Chapter 1, Level 7	Finish level having spawned less than 40 Biter zombies (starter zombies count)
Speed Run - Chapter 1, Level 1	Finish level in less than 240 seconds.
Speed Run - Chapter 1, Level 2	Finish level in less than 530 seconds.
Speed Run - Chapter 1, Level 3	Finish level in less than 640 seconds.
Speed Run - Chapter 1, Level 4	Finish level in less than 1080 seconds.
Speed Run - Chapter 1, Level 5	Finish level in less than 570 seconds.
Speed Run - Chapter 1, Level 6	Finish level in less than 780 seconds.
Speed Run - Chapter 1, Level 7	Finish level in less than 730 seconds.
Swarm	Reach 100 zombies alive.
They are billions	Kill a billion humans.
They are millions	Kill a million humans.
Under the wheel	Lvl 5, have 50 zombies rammed by racers.
We are billions	Spawn a billion zombies.
We are millions	Spawn a million zombies.
Who are you again?	Finish Chapter 1, Level 7.
Zombie tv	Finish Chapter 1, Level 5.
Zommm-BoOoOom!	Explode 1000 boomers.
ZommmbWeeee!	Chapter 1, Level 3, Make 100 zombies trip over.