Dammit, I was finally lucky enough to find The Bible, so I beat Mom's Heart without taking damage and saw the Devil room door... And then I opened the treasure chest and game was over. --- Don't be scared of nightmares; make them be scared of you.
I had heard/seen all the facts independently but had never pieced them together until now. I knew that killing the heart with no damage taken could open the way to Sheol before you beat the heart 10 times. I knew that a devil room could open after killing the heart. I knew that since the halloween patch, the only thing in said devil room is a trapdoor that leads down to Sheol (pre-patch you had the chance for a normal devil room). I just didn't realize that that trapdoor was your reward for killing the heart without taking any damage.
Relevant to your question, I assume that's the Devs' way of making you choose between your completion reward and an early trip to Sheol. --- "If you save my life, we will rise and shine so bright that the stars go blind and leave the sky." -- Seabound, "Castaway"
Yea I was pretty angry at myself for picking the chest over the devil room after my first mom kill. I still had an extra life and a full health pill on me, and full hearts, and was pretty much maxed out stat wise with brimstone, had 3 flies, an attack fly and steven floating around me.
feels bad man. --- try spelling this backwards if you're bored !