Ive had a problem with the game after i put it in fullscreen mode it made my game unplayable as i couldnt change the settings
Try deleting the Settings.sav file located here: C:\Users\YourUserName\AppData\Local\ShopSim\Saved\SaveGames
If you're having trouble finding it, reading this post (and its replies) should help:
https://itch.io/post/128793/view-in-topic
