Rotten Penny
AchievementAfterbirth+Unlock unknown
Achievement details
- Achievement number
- 388
- Description
- Unlocked a new item.
- Requirement
- Have 20 Blue Flies at the same time
How do you unlock Rotten Penny?
Source text onlyThe instruction is sourced, but its steps are not mapped yet.
Unlocked a new item.
Verified requirement
Have 20 Blue Flies at the same time
A structured unlock path has not been mapped for this achievement.
What unlocking Rotten Penny leads to
Source: bindingofisaacrebirth.wiki.gg
Imported 2026-09-13