Isaac Progression

Achievement

Buddy Baby

Earn every completion mark on Hard mode as Isaac.

In-game: “Unlocked a new co-player baby.”

Sources:Achievements Completion Marks

0 of 21 doneNext: The Womb

x

Stage 1any order

Greedier!
Ready
Donate 500 coins to the Greed Donation Machine.
Isaac's Head
Ready
Complete the Boss Rush as Isaac.
Lil' Chest
Ready
Defeat Ultra Greed as Isaac.
The Womb
Next up
Defeat Mom.
Reach Depths II and defeat Mom.
Sources:Achievements Womb

Stage 2any order

Blue Womb
Later
Defeat Mom's Heart 10 times.
After: The Womb
Mom's Heart defeats0 / 10
D1
Later
Defeat Ultra Greedier as Isaac.
After: Greedier!
Isaac's Tears
Later
Defeat Isaac as Isaac.
After: The Womb
Lost Baby
Later
Defeat Mom's Heart or It Lives! on Hard mode as Isaac.
After: The Womb
Mom's Knife
Later
Defeat Satan as Isaac.
After: The Womb
The Polaroid
Later
Defeat Isaac 5 times.
After: The Womb
Isaac defeats0 / 5

Stage 3any order

A Secret Exit
Later
Defeat Hush 3 times.
After: The Womb, Blue Womb
Hush defeats0 / 3
Angels
Later
Complete Chapter 6 (defeat ??? in the Chest or The Lamb in the Dark Room).
After: The Womb, The Polaroid
Fart Baby
Later
Defeat Hush as Isaac.
After: The Womb, Blue Womb
New Area
Later
Defeat Hush.
After: The Womb, Blue Womb
Hush defeats0 / 1
The D20
Later
Defeat ??? as Isaac.
After: The Womb, The Polaroid

Stage 4any order

A Strange Door
Later
Defeat Mother.
After: A Secret Exit
Cry Baby
Later
Defeat Mega Satan as Isaac.
After: Angels, The Womb, The Polaroid
D infinity
Later
Defeat Delirium as Isaac.
After: The Womb, Blue Womb, New Area
Meat Cleaver
Later
Defeat Mother as Isaac.
After: A Secret Exit

Stage 5

Options?
Later
Defeat The Beast as Isaac.
After: The Polaroid, A Strange Door

Stage 6

Buddy Baby
Later
Earn every completion mark on Hard mode as Isaac.
After: Mom's Knife, The D20, Isaac's Head, Isaac's Tears, Lost Baby, Fart Baby, Lil' Chest, Cry Baby, D infinity, D1, Meat Cleaver, Options?