Just came back to this a year after I last played it, and to see that to continue after day 14 you have to pay AGAIN is very disappointing. I understand software limitations can happen, but if I were to do something like this I would first figure out a way for people who already bought the game to receive it for free, such as obtaining proof of purchase and giving them a key to the second game, or at least find a way to compensate those who already own it. It just doesn't look good (imo) if you're not willing to do something like that.
Good luck with your game, but I personally won't be paying for it again.