Catch fire and put it out with water

Make the gorilla from the arena die at the highest point possible

Win 25 Warfare battles.

Beat 2 levels in a row without picking up any hearts

Let the block fall on your head in Thor's room

Come out of water on your last breath in Neptune's room

Let only one sword hurt you in Damocles' room

Kill Satan with Azazel

Beat 2 levels in a row without taking damage

Kill Satan with Isaac

Collect 2 of either Roid Rage, The Virus, Growth Hormones, Experimental Treatment, or Speed Ball

Beat the Basement/Cellar without taking damage

Hold 55 or more pennies at one time