Initial Impressions - essentially everything that popped into my head while playing through your map for the first time
It's too dark. Even for night time, with a window shining that much light and a candle on the other side of the room, it should be brighter overall, like
this image; see how, even though there is no direct light from the window, the entire room is illuminated? It might not be brightly lit up, but you can see every detail if you look hard enough. There are parts of the bedroom on your map that are pitch-black, where there is no detail visible. I like to call these "black-holes-of-death" because they tend to make for a non-immersive environment (at least for me).
The rain noise in the background is a nice touch, a very commonly used touch, but I like it nonetheless.
The spotlight is also nice, good good, you used a gobo on it. I didn't know about gobos for the longest time when I started mapping. They're life-savers. Did you know you can have animated ones? Those are pretty useful for water reflections. Let me know if you want an explanation on how to animate them. Alright, I'm done appreciating the pretty gobo.
Colour of the light is white. Not my first choice, but I'll let that slide and explain how to change light colour (and why you should change light colour) later.
Starting position angle is good; you have the player looking towards a light source, presumably where I should be headed, which tells the player where to go without letting them know you're giving orders. Bravo :D
Alright, there's nothing on the desk for me to observe. Just some tinderboxes and potions. You can put the items in the drawers, it just takes a bit of fancy camera angling and zooming. If you turn on the "place object on surface" it'll be a lot easier. Speaking of the desk, your desk door is off. The set is designed so you place the door in the exact same coordinates as your desk and they'll line up. No extra work needed! In your map, those coordinates are 0, 0, 2.75 (X, Y, Z) - I used the level editor to get those.
Nothing else of interest in the room, sanity's draining quickly (always reminded me of someone eating nachos), so it's best to get a move-on.
ASLKPEWITHWSFD-GAH DOOR! I was expecting a scare (in the form of a monster), nice to see you didn't rely on the monsters to do the scaring. Alright, my heart's stopped fluttering and my hands aren't shaking anymore (I'm easily scared... you'd think I would stop torturing myself with ATDD related things). Time to explore the corridor.
Long corridor, lots of windows, lots of walls, lots of floor, not much detail- chair. I like the chair. It makes the room more organic - well, less game-like and more realistic. Kind of makes me want to know why it's there. Lemme guess, Mr. Scary's going to break down that door and eat my face, right? Great. Let's avoid that and go to the door on the right. More pitch-blackness, a couple rats - interesting place for rats (the environment looks too sterile, no dust, no dirt, no particles in the air, no food lying around for them). Oooh a lantern.
Welp, I'm going to hide- asjflaeurtwfsd I can't control my mouse! Camping in a closet with The Brute just outside. That's cruel, using the lantern to trigger the brute. I like it though; you turned something that everyone wants and loves into a cruel monster-triggering item. It's like shock-therapy, you're going to traumatize me if you keep scaring me when I do stuff with the lantern. Speaking of which, that would be pretty cool, having the lantern trigger monsters (or just scary things) when it's turned on. I might use that for myself. Back to my closet.
So, pretty much, my tactic for these monsters is to just hide until they go away. I chose the closet in the lantern room. The doors to both closets were opened by me immediately upon entering the rooms because I don't trust you modders and your monsters :p Oh my, he's hanging around for quite a long time - I take that back, he just poofed to somewhere. Oh isn't that nice, he opened the door for me.
New room, looks like a dining room area-thingy? Lots of candles in there. Glad to see you arranged the books on the shelves each individually :D try rotating some of those book piles so they don't ruin the effect. Also, your bookcase is floating, causing it to clip through the roof. Didn't notice it until just now, but you might want to fix that. New room time!
Aw, come on :c the library cases are all identical. You don't have to create completely unique shelves for each case, but at least re-order them so that they don't look deliberately copied - maybe put the shelf that's the top on one to the bottom of another, swap a few of them around, delete a few books off of another, just a few little changes will make it look like you put a lot more effort into this. Good news though, they're not floating! :D Quick tip: next time you move objects by grouping them, turn off the grid snapping so they don't float up (assuming that's what happened in the other room).
Corners need welders, glad to see you threw in extension walls and made the ceiling higher for the chandelier. The welders will just make the corners look a little less odd. I believe the one you need is called welder02_concave and it's under the mansionbase wall set.
I hear rats, shall we move on to the next room? Yes! Nice storage area, same problem with the shelves all being identical, though. It's a pain in the butt to individualize them all, but it's so worth it in the end. Found the key in the desk. Turned around and there were statues. I was expecting another brute, but this made me happy c: Thanks for not using a monster. The knights aren't extremely scary, but they definitely startled me - it's a good way to start building tension. The wine bottles in that wine shelf look a tiny bit odd, I would take a look at how
these bottles are arranged on a similar shelf and try something like that. Although, gravity-defying bottles are pretty neat too.
My stomach growled and it scared me. Thought I should share that. I'll hold off hunting for food until I've finished this map. Oooh opened door with the key and found a sudden change of map, that was unexpected. Unless you have a good reason for using the blue torches, I would use the orange ones - they look a lot nicer in most cases (but that's just me). Also, your ceiling is missing down here.
Lighting
Spotlights are wonderful, candles are strategically placed, but this point needs a lot of improvement. Mainly with
this. I'm standing in a lit corner, most of your map is completely pitch-black. In cases like
this, where I'm standing in front of a door and cannot see it, the whole lighting thing becomes much more important. I would advise using a boxlight. Just one that covers the entire map, and changing its colour to 0.05, 0.05, 0.05 (R,G,B) so that the door is visible even in the kind of situation demonstrated by the links.
There are also areas of lighting where you have two sources of light very close to each other, but there's pitch-blackness in between them. I'd advise taking a look at
this tutorial for some help with lighting. If you're still stuck, feel free to ask me (pm or reply to this message, I'm always available for help).
Lastly, the colouring of the lights is just plain booooooring. I'm talking about the spotlights and their pure whiteness. It's not going to kill me but, if the light's were given a slight blue-tint, it would add to the atmosphere so much. It would suggest that it's night-time and not just a very dark day.
Scares
You seem to have an understanding of
this curve's applications to virtually everything. Although the Fichtean Curve originally applied to a story's plotline, it's also very important for building tension and scares. Whether or not you did this intentionally, keep doing it! :D
Level Design
The flow was quite decent, I didn't get lost and I knew where to go. All in all, that's pretty impressive for someone with just 3 days of experience!
Music
The rain was nice, there was no other background noise, but the rain is sufficient.
Overall Atmosphere
It wasn't very easy to immerse myself in your game world, but you did quite nicely. You seem to know what assets look good where and, although the maps could use a lot more decorating, you're doing quite a good job. I would try adding in some particle systems, decals, and debris to make the rooms a little more interesting and messy.
Scripting
Seems like you're doing pretty good there already. If you want anything clarified, I can help, but I'm not the best person to ask as scripting is my (very) weak point. Of course, you're free to pester me all you want about scripting, I'm just warning you ahead of time that I may not have all the answers (or any of them for that matter).