Do this if no option to import Rebirth save file shows up on Repentance
If you download a 100% file, immediately go to the "Secrets" menu and scroll through the entire thing. This ensures the game registers every unlock in your current session, preventing weird "Locked Achievement" bug-outs later. binding of isaac repentance 100 save file
Before launching the game, right-click Isaac in Steam → Properties → General → Uncheck "Keep games saves in the Steam Cloud for The Binding of Isaac." If you don't, Steam will overwrite your new 100% file with the old cloud version. Do this if no option to import Rebirth