Use all of the coop moves.
Collect 32 golden teeth.
Beat the game.
Get a x20 multiplier.
Kill Fat Lu with a shotgun... at point blank.
Use all 8 finishing moves in one level.
Kill 6 enemies with the same shotgun.
Beat a whole level without picking up weapons or objects.
Feed an enemy to a crocodile.
Knock one rider off his scooter with a bat.
Collect every golden statue.
Find every secret area.