It wasn't just a feeling. The reason Quake felt like a distinct shift was that it was the first proper 3D engine in an FPS, allowing for much more interesting level design and player freedom. Doom was still built on the hacky 2.5D engine from Wolfenstein.
>Doom was still built on the hacky 2.5D engine from Wolfenstein.
That's not true at all. Wolfenstein 3D was a raycasting engine based on cubes. Doom used BSP trees and allowed for much more varied level geometry without right angles everywhere (although there still were no sloped floors).
Let me rephrase that. Doom extended the technique used in Wolfenstein, which is 2D maps and sprites, and movement in the 3rd dimension was limited. Quake used a proper polygon rendering engine. In any case, it doesn't change my point that there is a discrete change in the rendering tech between Doom and Quake that accounts for the difference in feel.
Doom-to-Quake was a bigger technological leap, going from a hacky 2.5D raycasting engine to a fully polygonal 3D environment and renderer.
But Wolf3D-to-Doom was a bigger gameplay leap. Doom could do enormously more with level design and the visual experience than Wolf3D could. Quake being fully 3D didn't really do all that much for the player experience over and above Doom.
Out of the box, Quake was a lesser experience indeed.
But the engine was highly mod friendly. I think i have at least a couple of CDRs somewhere (if they are still readable) Stuffed with zips downloaded from Fileplanet.
Everything from grand projects like Team Fortress, to small one man mods that was not much more than a collage of weapons.
This in large part because the game logic was implemented using quake-c, and the compiler was freely distributed.
