I can confirm that I downloaded and played this demo with no security issues - not a scam!
First off, the art is really beautiful. Particularly the backdrops. The wintry, gothic atmosphere is rich and lovely. Feels very Crimson Peak. Very appropriate soundtrack, too.
The sprites look great, too, but the fact that they don't have any changes of expression leaves them feeling a bit lifeless. A change of outfit or two for our heroine would be great as well, since there are scenes where she would hypothetically be in a nightgown or a towel, so seeing her perpetually with her hair coiffed and gown on takes you out of it a bit.
Concerning the writing, I would recommend some kind of visual difference between narration text and spoken text to help the brain break up the action and "hear" the spoken words.
As far as the quality of the writing goes - the tone is established well, it's very serviceable, although somewhat sparse and lacking some of the lushness that the art has. The heroine bears some hallmarks of being frustratingly passive, although maybe further development will reveal more of her.