Here is the full list of all 20 Jay and Silent Bob: Mall Brawl achievements.
Liberate a baby from his stroller.
KO Adoughbo.
Smack an old lady.
Beat up Mooby.
Steal a skateboard.
Steal a hockey stick.
Pick up a sockful-o-quarters.
Die in the first level.
Beat up the Easter Bunny.
Steal a bra.
Smash the crane game.
Smash a mannequin.
Launch an air hockey puck off the ground.
Get hit in the face with a pair of panties.
Throw an enemy at another enemy.
Unlock hard mode.
Beat hard mode.
Clear the shopping cart run without taking a hit.
Clear the game in one run without a Game Over.
Clear hard mode in one run without a Game Over.