Collect the Witch Talisman and complete both witch quests.

Don't harm the Mad Family.

Defeat the Pumpkin King in mortal pumpkin combat.

Defeat both Mecha Imps and their taunting Imp pilots.

Smash a severed hand.

Defeat the Stained Glass Demon in the Hilltop Mausoleum.

Kill something with your own arm.

Return to Dan's Crypt and smash down the secret wall.

Get a Game Over 5 times.

Throw 42 Chicken Drumsticks.

Defeat Lord Kardok.

Collect every weapon.