I watched a speed run and without doing the cheesiest strategy of waiting for certain items, a guy got to the final fight within 30-40 minutes but got instantly 1 shot because he only had a half of a heart, he used Judas too.
The real finish unlocking the polaroid and fighting the blue baby in the chest.
But congrats of beating mom's foot (it doesn't count as beating mom though. )
I have the achievement "I killed mom" so I count it
That was a glitch apparently. You can fight him in the game as a boss, but he isn't the final boss.When does Triarachnid come into play?
He'll have to do the challenge to unlock mega fetus. Besides, brimstone > *.Game is a lot more fun with a gamepad and mapping the buttons using Joy2Key. The Wrath of the Lamb DLC is a must-have. Trust me, get the Mega Fetus and you'll understand
But yeah, the game is pretty tough in the later levels, especially if you don't get good powerups/bombs/keys/cash and increase your hearts early on.