Hmmm, I just tested it and it's working properly. I think maybe you must have pressed save while you've just loaded the game. This overwrites your progress earlier. A mistake like this will always happen especially since the game relies on reflexes so on the next version I will add more save slots and a load/new game option in the main menu. A new menu will be created for saving and loading to avoid sudden overwrites. I will also change the target save folder from the game's own folder into the user folder next time to make the saves more robust. Thank you for posting about this!