Just the beginning...
Not unlocked yetComplete City - Stage 1
Tanked
Not unlocked yetDefeat the city zone boss
Killing Spree!
Not unlocked yetKill 1,000 enemies
Wrecktacular!
Not unlocked yetKill 10,000 enemies
Albert Einstompped
Not unlocked yetDefeat the lab zone boss
Gave the Devil His Due
Not unlocked yetDefeat the hell zone boss
And Stay Off Our Planet!
Not unlocked yetDefeat the alien zone boss
The Road Less Travelled
Not unlocked yetSurvive the hard route in City Stage 2 without dying
Chaos Commando
Not unlocked yetKill the first boss without killing either turret on the tank on Normal mode or higher
The Righteous Path
Not unlocked yetUnlock the laser cannon in Lab Stage 2
Faster Than a Speeding Bullet
Not unlocked yetKill the second boss without dying on Normal mode or higher
No Way Out
Not unlocked yetDestory all alien spaceships in Hell Stage 3
Bullet Hell
Not unlocked yetKill the third boss without killing any lava spitters on Normal mode or higher
Every Nook and Cranny
Not unlocked yetUnlock the laser cannon in Mothership Stage 1
Secret Stash
Not unlocked yetFind all the secrets in Mothership Stage 3
Splatterfest
Not unlocked yetKill the fourth boss with at least 3 slimes still alive on Normal mode or higher
Killer Kombo
Not unlocked yetGet a 300 combo
Home Defence Force
Not unlocked yetComplete the City Zone without using a single continue on Normal mode or higher
Prodigious Offence
Not unlocked yetComplete the Lab Zone without using a single continue on Normal mode or higher
Overlord of the Underworld
Not unlocked yetComplete the Hell Zone without using a single continue on Normal mode or higher
Master of the Universe
Not unlocked yetComplete the Mothership Zone without using a single continue on Normal mode or higher
True Master
Not unlocked yetComplete the entire game without using a single continue on Normal mode or higher
Despiration Tactics
Not unlocked yetKill 1000 enemies with the single pistol
How the West Was Won
Not unlocked yetKill 2500 enemies with the dual-pistols