In the end this just became tedious. While you control your character like an FPS, this is almost a point and click adventure. Most missions require you finding an object, combining it with something else, then clicking the combined object on a locked passage. Occasionally you will find yourself hiding from a zombie-like monster (Outlast style). But it is literally a monster—one enemy type the entire game. There’s also some sort of mechanic where you must maintain your sanity, but it’s not interesting at all.
All this would be a moot point if there was a compelling story. Alas, there was not. The backstory is developed as written notes and the occasional narrated flashback. But it’s so easy to forget what it’s about since you, the player, are not involved in the story telling. Something about an orb and a shadow. Who cares. Pass on this one.