Stop playing immediately. Use a file recovery tool like (free) on the %AppData%/LocalLow/OldB1ood/FeedandGrowFish folder.
folder from the Steam userdata path to a separate drive or a zipped folder after each session. Restoration: To restore a backup, delete the current save in the feed and grow fish save file
On non-Windows systems running through Steam Proton: Stop playing immediately
Players occasionally report issues where the game fails to save or even launch. Feed and Grow: Fish - Jacksepticeye Wiki feed and grow fish save file
Whether you lost your progress after a PC crash, want to skip the early game grind, or simply want to dominate the ocean as a max-level Leviathan from the start, mastering the save file is your golden ticket.