To transfer your progress from the demo version to the full version, you must use manually saved save data.
Please note that AUTO save data cannot be transferred.
We apologize for the inconvenience and appreciate your understanding and cooperation.
Important Notice: Regarding Save Data Transfer from the Demo Version
Source: Steam Community (opens in a new tab)
Build and release context
Recorded Steam release date:
Within one calendar day of this post (UTC). The listed date does not establish an exact launch time.