Haha, actually, I'm struggling to get that PS1-ish feel to my scenes, I think there's too much details for a game of this era.
I mean, using low-res textures and lowpoly models is a thing, having the right amount of detail in a scene is another.
You, Sir, seem to have serious lightmapping skills ! I'm not very fond of the all pitch black ambience, but it looks good from what I can see !
I love the colors on your last screenshot.
An idea that just came to my mind, have you thought about putting an hanging neonlight in front of that hole in the wall, right behind those iron bars ? 'could be very interesting, visually speaking.