"I unlocked everything, but the Steam Achievement didn't pop." Solution: Steam achievements are tied to actions , not save state. You must trigger an "action." For example, if you edit The Lost to have Godhead, you need to pick up a new item or beat a boss to force Steam to re-check your secrets. Go into a run, pick up a penny. The achievement will fire.
"It's a single-player (mostly) game. Your save file does not affect my enjoyment. Gatekeeping item unlocks is weird." The Binding Of Isaac Repentance Save Editor
A visual grid of character post-it notes. You simply click the icons to mark them as completed (Normal/Hard, Boss Rush/Hush/Mother/Beast/Delirium). "I unlocked everything, but the Steam Achievement didn't pop
Edit the grind , not the gameplay .
Launch IsaacSaveEditor.exe . Click File > Open . Select your repentance_persistentgamedata1.dat . The achievement will fire