You can also get the codes on Subscribestar.
(Don't get me wrong, please, I just want to help. I don't care if you support it or not, it's unfortunately not my game.)
Same thing.
This is the aftermath of the Cold War between the US and Red China. Union Pay is blocked in the US, UK, Australia. And consequently, companies affiliated with these countries do not work with the Chinese payment system. Yes, I can purchase Visa or MasterCard, but the cost of that (about 600$) is not worth it to pay 20-30$ for support of some game (it's not a necessity).
As for saving - in critical moments triggers autosave, as for ability to save in the most critical moments of the game - this is typical for many projects, I'm used to it.
For me the most painful and critical moment - mini-games, because of them I gave up with attempts to continue playing this game, everything else is nothing.
But thank you for your comments, it's nice to see that you are not alone.