So I am starting work on the game. Thanks in large part to the Löve port of rot.js, I have an engine up and running where you can load up a map (built in Tiled) and walk around in it. Here's what it looks like currently:
It has line of sight working, movement blocking working, but there are no enemies or moving between levels or anything like that working yet.
That car is like the stairs in most roguelike levels - you go there to leave the level and go to the next place.
Eventually, the maps will be "procedurally assembled" - as opposed to procedurally generated - from a series of pre-made "geomorphs", which will be pieced together using a procedurally generated mystery as a guide. (That's the plan, anyway!) For instance, the "woodland clearing" map will be the same in every game, but whether it shows up will depend on the mystery it generates, and it will have spaces where interesting things that further the mystery can be placed, such as unmarked graves, mysterious stone altars, sites of ritual murders, etc. The maps themselves are not procedurally generated, but how they are assembled will be, in service to the higher-level mystery.
Having learned the hard way that you should always start with your games being able to be saved and loaded, I am starting out with saving and loading in mind. So one of the first things I have written is a save and load screen. My goal is to keep save/load parity with all game features continuously throughout the project.
The tileset is inspired in large part by the old Ultima games, which used a heavy black palette. I've always liked the look, and I thought the unusually large amount of black pixels would lend itself to the feel of a horror based game, so I ran with it. I'm pretty happy with it so far.