Beat the game without continuing.
Beat the game without using a special attack.
Defeat Boss 'Jet' at the end of Stage 2 -- with Game Settings set to Hardcore.
Score 800,000 points in one game -- with Game Settings set to Hardcore.
Complete an online co-op game.
Beat 10 opponents in online versus mode.
Beat another player in an online versus match.
Beat the fourth boss.
Beat the first boss without dying.
Kill 10 enemies without losing your weapon.
Wield the knife in single player or co-op mode.
Wield the pipe in single-player or co-op mode.