Bronze

Untouchable
Go unharmed for an entire level, without restarting from a checkpoint.

Turbo
Complete the game in less than 80 minutes, in one session without restarting from a checkpoint.

Vigilante
Eliminate 20 bad guys in 101 seconds.

Strong Arm
Knock 100 people over, by throwing other people into them.

Retaliator
Perform 200 counter attacks.

Exterminator
Perform 250 finishing moves.

Shield
Dodge or block 25 incoming attacks

Silver

Psycho
Complete the game in Rorschach mode.

Hero
Complete the game in Nite Owl mode.

Thief
Find all abilities and pick-ups in Rorschach mode.

Detective
Find all abilities and pick-ups in Nite Owl mode.

Gold

Teamwork
Complete the game in co-op mode.