If your fish dies or your save becomes corrupted, simply copy your backup files and paste them back into the original SavesDir folder, overwriting the current files.
On Windows systems, Feed and Grow: Fish typically stores its save data within the game's installation directory rather than the standard "Documents" folder. feed and grow fish save file
Ensure Steam Cloud Sync is enabled in the game’s properties to automatically store a copy of your progress on Steam’s servers. Managing Save Files and Cheats If your fish dies or your save becomes