It saves progress just fine. Can't say what your doing wrong.
Theres two ways to save progress. DL a zip file or upload to the server and write down the number it displays in the popup. Simple really.
This is rare game. The MC goes into action fast. Unlike almost every other game. Tried a handful of game and even up to 3 hours of play. Still no content or tasks leading up to the reason these games are downloaded.