The good:
Nice and fitting art style
Thematic and beautiful music
Good writing that evokes the time of the setting and the horror elements well

The Bad:
No meaningful gameplay, just move all cards to matching rooms and click activate. Even if done randomly you will eventually beat the game.
While the art, music and writing are good the game does not pull them all together and make them into something more.

Conclusion:
The gameplay was not engaging and did not contribute anything to the good parts, it basically just made me waste time. This short story while decent did not deserve 9 hours of my time when it could have been conveyed in 1-2 hours. I do not think that the experience is worth the asking price, if you are just in it for the story you would get better value from an audiobook.

10 hours in and enjoying the game as a means of relaxing after work with a drink. Not terribly hard, but interesting story.
Make it to chapter 8 and minor obstacle erases your bonus cards if you leave them in the room with it.
Suddenly something happened that shoved the monster into my card storage space.. Which erased all of my bonus cards ive spent a while building up, plus other supports and things i need to beat the game. Nevermind an enemy i need to beat keeps spawning in an area i cannot get the bonus cards to beat.

Since it single save files and overwrites each time, if i want to get back to where i was, i need to start all over from the begining.

Smoke this ♥♥♥♥.

While parallels could be drawn between this game and Cultist Simulator/Book of Hours, at least in terms of mechanics, I would not be surprised if this game's core inspirations lay in the classic board-game Arkham Horror. That's definitely a positive in my book, of course, given my own tastes in literature. (and the time I played it at uni)

While Cultist Simulator and Book of Hours are a bit more free-form, I'd argue that Horror at Highrook is more condensed and focused by comparison. Granted, I've sunk many more hours into Book of Hours, but I very much enjoyed Highrook's more directed and character-driven investigation of a spooky old manor.

Needless to say, I do recommend this game for people who like the Secret Histories games. It's a solid, reasonably-priced experience that lasts about as long as it needs to, so definitely check it out.