I just took the time to beat this after I was stuck at the Water Monster part in the storage for so long haha.
Alright then it's review time!!
Mapping: Mostly I think this is really well done. There are tons of interesting, and fresh environments which is nice considering you only used the original assets. There are a handful of mapping errors here, and there such as billboard problems, skybox leaking through planes, etc. Nothing too serious though!
Atmosphere/Scares: The atmosphere is done very well, and is the main thing carrying the "horror" of this mod. It's further achieved by some scary sequences which are amplified even more with creative gameplay happenings.
Puzzles/Gameplay: For me I think the puzzles are for the most part done very well. Many of them are purposely left vague as to how to solve them, and while you may be stuck on them for a bit they are by no means unsolvable which means you'll feel great when you finally do it.
There are a few which I think are "too" vague though such as the boss battle which I think may have been too unclear on how to beat. There are also a few sections of the game which may just be a bit too difficult which can take you out of the game, such as the water monster part.
I also really like the addition of relics as an optional collectible. I only found two though haha.
Story: This was obviously left purposely vague, and I think for what it's worth it achieves what it set out to achieve quite well.
This may be a personal preference though, but I think it was TOO vague. I mostly enjoy stories which have their main focus very fleshed out, and clear by the end with only side plot-aspects being vague if the creator wants something like that in the story. In my opinion, if even the main plotline is too vague it can sometimes leave the player without a sense of clarity when they finally finish the game leaving them unsatisfied.
Also here's how I interpreted the plot:
Verdict: Very creative mapping, scares, and overall gameplay makes this a stellar experience which may suffer just a small bit from its plot being a bit too vague
8.8/10