Looking at games

In looking at game levels, deconstructing them and learning about how they are comprised, there are several factors/illusions that can fool the player into believing it is an authentic world they are playing in. Things such as invisible barriers that mean the objects behind cant be reached. If this is the case, it can often be that it is a single plane or cube, with a single 2d photo/texture on it. This provides the illusion of multiple buildings and huge levels, without lots of designing.

The first game i want to look at is the original, floppy disk format, dos DOOM on the pc. Being released early 90s, it was a greatly received game that has a huge following. (the Doom franchise is still making money today with titles for xbox and ps3 available)
The original has charm, great narrative, maximum game play and most importantly is simply constructed using basic shapes and great textures.
This first image, has such simplicity to its layout. The floor texture in a basic repeat pattern of rock made seamless, the walls just basic planes with a juxtaposed texture to it, making it stand out and define the edge of the floor.
But its this 'illusion' bit that i find most interesting. The buildings and sky in the back are just one big image or plane, with an illustrated dystopian sky for the rest of the first person view. Its very clever. As a child i never noticed this. But recently this sort of 'magic' i find fasinating. There are so many aesthetic suggestions that can be made using abstracted images to create a great atmosphere within a game.

This is from Doom 2. The grey texture on the walls and the floor is something akin to the type of aesthetic effect im after for the interior of my game level. These arn't even seamless textures. You can clearly see the repeat in the walls highlights and shadows. But this doesn't take away from their effect.
I also think the dashes of colour coding that are used to represent that different colour keys open different colour doors.
Within the context of my game level i would like to use this juxtaposition of colour to highlight the objects that my robot has collected.

This is an Image from Ghost Town 2. Not a lot about this game appeals t me. It was just one of the few examples (in game) i could find of the steel stairs and corrugated iron effect that i am after.
Its this sort of texture...

Im just after something a lot more metallic, rusted and broken down. Photoshop and illustrator will most definitely be used. However there are many functions within Unity that will allow for manipulation and texturing to.

This is a grab from Fallout. This game has the perfect dystopian vibe that i want to try and create within my level. It seems to have partical effects and barren landscapes that are open and free roaming.

There are others like Bioshock, Stalker, Half Life 2, Unreal tournament, Quake.. that all employ similar techniques. Especially in the earlier editions.