[hazzen]

Descent came out over a year before Quake and was full 3D (except the annoying hostage sprites). It may have taken advantage of being set in a mine to have twisty passages that obstructed views, but it did have its fair share of wide open spaces (most reactor rooms, for instance). I think the reason Quake gets all the credit is due to its popularity, not for being the first.

[jongraehl]

Descent used affine texture projection, which makes texels slide around as your viewpoint changes, unless extremely small polygons are used (they weren't). It also had extremely simple lighting (intensities set at vertices, interpolated in a simple gradient in screen space like the texture projection). Neither of these things means you're wrong in calling it "full 3D", of course. I don't recall if the topology allowed room-internal objects other than the robots; I think it did.

[petercooper]

There was also Driller in 1987 which had full 3D representations though you could rarely take advantage of it. It was based on the Freescape technology which I played with in 3D Construction Kit in 1991 and that was definitely full 3D in terms of movement (though not a game in itself).

[tincholio]

Was this similar to Oblivion? Where you had to plant some gas valves to relieve the pressure on the planet? Awesome, frustrating little game :)