The Binding of Isaac: Rebirth

I swear they have lowered the drop rate of Soul Hearts from the original game. playing as ??? is torture, I've gone 3 or 4 floors clearing every room and never finding a single soul heart. It makes every hit that much more frustrating because the health is so hard to get back.

I've had runs where I have gotten absolutely god-like combos of items offensively, but finding not a single soul heart and falling to the first or second boss because the game will throw me up against a bullshit boss like Dingle or Haunt which are hard to avoid getting hit on.

That's why I usually mix my Blue Baby runs--well pretty much all my runs--with both Soul Hearts and the new Black Hearts. Items that grant Black Hearts are a lot easier to find, and honestly they're a lot better to pick-up anyways.

Also: I don't know if you knew this or not, but the skulls in the later areas have a chance to drop Black Hearts, amongst other things, when destroyed. Likewise, the Blue/Purple Flames can be destroyed by bombs and they have a 50% chance of dropping Soul Hearts.