Your progress is precious. Locate the save file here:
C:\Users\[YourName]\AppData\LocalLow\LunarMilkGames\JamPackedLineTale\
Copy the save.dat file to a cloud folder or USB drive weekly.
The original indie developer often releases the PC build on Itch.io. Search for "Jam Packed Line Tale" by the developer "LunarMilk Games" (name may vary). The download will be a .zip file containing an .exe installer. jam packed line tale pc download work