Morally Superior
Complete the game as Nite Owl.
36 
Street Justice
Complete the game as Rorschach.
36 
Friends Forever?
Complete the game in Co-operative mode.
36 
Martial Artist
Perform all 8 Nite Owl combos within 60 seconds.
15 
Feral Fighter
Perform all 8 Rorschach combos within 60 seconds.
15 
You Tag 'em - I Bag 'em
Eliminate an enemy that your partner has knocked down or thrown in your direction.
11 
Focus Fire
Take down 10 enemies in a row finishing off each of them before doing damage to anybody else.
11 
Electric Explosion
Hit 14 enemies with a single electrify armor blast.
8 
Rrarararghgh!!!
Sustain a single rage mode for 60 seconds.
8 
Ping Pong
Hit at least 4 different enemies while building up a combo.
8 
Unending Combo
String a single uninterrupted combo that's at least 10 hits long.
8 
Gentleman
Complete Chapter III without hitting any ladies before they hit you.
8