I wish you could explain basically your mental image of the game here. You described the lore, but let's go technical. How you see it? So i can see how much i can help!
I can see it being a cross between the viewpoint style of Silent Hill 1
http://www.emuparadise.me/fup/up/53247-Silent_Hill_%28J%29-1.jpgWith the aesthetic of a ship or that one lab section in Resident Evil 1. The characters would look human but with the PS1 restrictions set they'd be more poliginal or blocky like Resi 1 or Silent Hill. The art design that I'm shooting for is 'realistic' I want the enviroments (even with the self-imposed limit) to look like what they're supposed to, a high tech 'mid-00's' Antarctic Research base that was secretly built inside of a large cargo ship.
Think tight shiny hallways, heavy watertight compartment doors, claustrophobic rooms. While the rest of the Cargo Ship is partially flooded, dark to where you need a flashlight to see (or your vision adjusts to the dark), rusted doors and hallways, and some areas that look well preserved when the power flickers back on.
I want The Victim monster to look similar to the player character, but spazes out and floats around like a puppet on strings, I want the sounds it makes to be very human (AKA: blood filled breathing, coughing, beginning for death, incoherent mutter, and sometimes distorted radio chatter like in PT). I want the player character to be somewhat customizable, I want the clothes they wear to dehumanize them (heavy coats, balaclava, etc..), and I want their voice to only come out when they go insane, (See: "They're watching... *wimpers* w-why are they always watching!?").
I want the guns to look like something a special task force would use, highly customized AK-47s, MP5s, and M4s. To give the player some false sense of, "I have great weapons, nothing can stop me!" But quickly realize that even with, what is for the time, highly advanced weaponry known to kill in seconds; but is actually like shooting foam darts at a pissed off gorilla.
But at the same time I don't want very many, maybe two of each weapon category. One New and One Old for each weapon type: (OLD)AK-47 (NEW)M4, (OLD)Tommy Gun (NEW)MP5, (OLD)Double-Barrel Shotgun (NEW)Pump-action SPAS-12, (OLD)357. Revolver (NEW)Glock-17, etc....
I want the majority of the outpost section to look like it came out of a apocalypse bunker, everything is clean, organized... better analogy: Think of Vault 101 from Fallout but designed for four people (there won't be multiplayer, but the hint that there would be more probably furthers the isolation).
That's currently all I can put into words.