First Versus
Beat another player in an online versus match.


Kill Jet
Defeat Boss 'Jet' at the end of Stage 2 -- with Game Settings set to Hardcore.


Knife Wielder
Wield the knife in single player or co-op mode.


Online Co-op
Complete an online co-op mode.


Perfect Boss
Beat the first boss without dying.


Pipe Wielder
Wield the pipe in single-player or co-op mode


Psycho
Kill 10 enemies without losing your weapon.


Fourth Boss
Beat the fourth boss.


Hard Win
Beat the game without using a special attack.


High Score
Score 800,000 points in one game -- with Game Settings set to Hardcore.


Online Warrior
Beat 10 opponents in online versus match.


Perfect Win
Beat the game without continuing.