Getting achievements from save file

[Ciocolici]

Hi guys!
I have just bought the game on steam. I fully beat and completed the game a long time ago on Amazon Games (got it for free through prime). I still have the save file, it is a 100% save file.

Usually, games autodetect this stuff and auto-unlock the achievements, but it was not the case with this game. I started the save file and yet no achievement popped up.

Does anyone try this before? Do I now need to fully replay the game or am I doing something wrong? Thanks!