The Tweaking of Isaac! Following items have been adjusted to be more generally useful and/or have added synergies; other's have been adjusted in their power or cost slightly:

Yum Heart, The Bible, The Box, Eucharist, Boom!, Head of Krampus, Empty Vessel, Breath Of Life, The Necronomicon, The Negative, Dataminer, Butterbean, Money = Power, Analog Stick, Skinny Odd Mushroom, Number One, Inner Eye, Lord of The Pit, Dead Onion, Tiny Planet, Purity, Soy Milk, Kidney Bean, Friendly Ball, The Bean, Blood Rights, Isaac's Tears, Betrayal, The Wiz, My Reflection, Technology 2, The D20, Luck Foot, Eve's Mascara, Stem Cell (trinket), Stem Cells (item), Spider Butt, Lost Cork, Eden's Soul, Anarchist Cookbook, Dark Prince's Crown, Camo Undies, There's Options, The Body, Mega Bean, Sissy Longlegs, Common Cold, Wire Coat Hanger, Missing Page 2, Book of Sin, Bursting Sack, Plan C, Aquarius, Aries, Pageant Boy, Mom's Heels, Mom's Eyeshadow, Mom's Lipstick, Mom's Pearls, Mom's Purse, Mom's Underwear, Mom's Perfume, Maggie's Bow, Brother Bobby, Sister Maggy, Headless Baby, Monster Manual, Abel, Mine Crafter, Holy Water, Celtic Cross, Magic Fingers, Ghost Baby, Ludovico, Ouija Board, Scissors, Dead Bird, Cupid's Arrow, Bob Transformation

General changes:
Contact damage dealt to Isaac while holding a golden heart applies midas touch to the enemy
Feared enemies take 20% more damage
Charmed enemies take 20% less damage

Following link has the full spoilered list of changes:
https://hastebin.com/nanakihaza.sql