It is called the "Get That For Me Jeeves" challenge. You may start as any character with the starting item; "Mr. ME!" The only rule is that you may not collect any consumable at all. No coins, no bombs, no keys, NO HEARTS, no batteries, no cards, runes, or pills. (The G0NE S00N seed helps get rid of them all) You MUST use Mr. ME to; bomb open any rock, open secret rooms, unlock locked doors, open chests, purchase anything, pick up trinkets (which are allowed), and most importantly, pick up ITEMS. You can buy ANYTHING from the shop. Easy version adds the 9-volt and/or the ability to pick up hearts. Final boss is to open the golden door with Mr. ME and beat Mega Santa. Seems enjoyable to me, I'm sure you can make something entertaining out of this. I suppose we'll see. Have fun!