To do 100% you have to start with a new save file, if you don't know how to delete the entire game progress then follow these steps:

1. go to Properties and disable Steam Clouds, with the translation from Polish to English "Save saved games in Steam Cloud for Ib" to delete the game progress
2. enter Local Files and then press Browse..., enter www file, then save and delete AnotherNewGameMk2.rpgsave and fileX.rpgsave from the folder (except file1.rpgsave because it is a file with auto saves). In case it is recommended to create a backup copy, but it is enough to move this files to an empty folder and after a run move them back to the save file

thanks for reading and have a nice running