Challenges

Alphabirth adds new challenges The Binding of Isaac: Rebirth that each unlock specific items, trinkets, or pickups for Isaac on later runs.

Name	Pack	Description	Items	Unlocks
Empty		Only active items spawn, use Void and Abyss to complete the challenge.	Abyss + Void	Fehu (Rune)
Exploding Head Syndrome!		Isaac is blindfolded and only shoots transcendent ipecac tears in the direction he moves.	Pseudobulbar Affect + Ipecac + Continuum	Glitched Pickups
Faust		Isaac starts with 12 heart containers; every floor he is automatically teleported to the boss room. He must use his 100% "Deal with the Devil" wisely as he has no access to treasure rooms or shops.	Emperor's Crown + Goat Head	Emperor's Crown
For The Hoard!		Use your bums and damage upgrades from Hoarder to hoard every pickup throughout the run.	Hoarder + Bum Friend + Key Bum	Naudiz (Rune)
It Follows		Avoid the Hush laser that slowly follows Isaac.	~	Apparition
Restless Leg Syndrome!		Bombs spawn at Isaac's feet if he stands still for longer than 2 seconds. The damage boost from Hot Coals further encourages continual movement.	Hot Coals	Sowilo (Rune)
S#!7iest Day Ever!		Isaac is blindfolded and must use Brown Eye poops as his main source of damage.	Brown Eye + Brother Bobby + Nun's Habit + 9 Volt	Brown Eye
The Collector		Isaac must choose between using pickups traditionally, hoarding them as a way to get extra damage from Hoarder, or absorbing them with Cauldron to gain extra items.	Cauldron + Hoarder	Gebo (Rune)