BOOM! HEADSHOT!
Not unlocked yetKill 4 enemies by hitting their weakspot with one Sniper Rifle clip.
Legion
Not unlocked yetReach wave 10 in Survival on Hard difficulty.
Without Number
Not unlocked yetReach wave 15 in Survival on Hard difficulty.
Scatter Brain
Not unlocked yetReach wave 10 only having built Blocks and Scatter Lasers.
Spray and Pray
Not unlocked yetReach wave 10 only having built Blocks and Gatlings.
OVER 9000!
Not unlocked yetReach wave 10 only having built Blocks and Lightnings.
Fully Covered
Not unlocked yetBuild one of each Tower on Arc.
Chill, Man...
Not unlocked yetUpgrade three Slow Fields to max level.
599 US Dollars
Not unlocked yetFully upgrade three towers.
You shall not PASS!
Not unlocked yetBuild 50 Block Towers during one Build Phase.
If you Replace the Working Parts...
Not unlocked yetUpgrade Towers 250 times.
...You get a Different Machine
Not unlocked yetUpgrade Towers 500 times.
It's Cool, I've got this
Not unlocked yetSurvive a wave without spending any Resources in previous Build Phase.
(See?) I've got this
Not unlocked yetKill an entire wave without aid of towers on Normal or higher difficulty.
Automagic
Not unlocked yetKill an entire wave in singleplayer without using your weapons.
Reanimator
Not unlocked yetTeleport 200 times.
Old School
Not unlocked yetComplete a level without teleporting.
Bang for your Buck
Not unlocked yetKill an entire wave only using the Assault Grenade on Normal or higher difficulty.
Martyr
Not unlocked yetKill an enemy with a grenade while being knocked back.
I Said STOP!
Not unlocked yetFreeze an enemy in a max level slow field.
Seven Sisters
Not unlocked yetFind the Babushka Doll on Mine.
Lunch box
Not unlocked yetFind the sandwiches on Bridge.
Meet the President
Not unlocked yetMeet the President on Arc.
Big Game Hunter
Not unlocked yetShoot 9 Strawberry Fishes.