Unfortunately, the demo is no longer available to download anywhere since:
1: It was a bad representation of the game, since the loading times were abysmal, making it close to unplayable on some computers, and there was a bad visual error visible on some computers as well. There were a lot of quality-of-life things missing as well, making the entire experience much less enjoyable than needed
2: Those who play the demo will still be forced to replay some of the same things in the full game, particularly the pretty lengthy intro, since savefiles cannot be transferred from the demo to the full game
Sorry for the inconvenience!