Wolfenstein wasn't true 3d. It was 2d from a first-person perspective. There was decidedly no up and down in the gameplay. I'm not talking about the graphics being quasi-3D -- I mean a game that legitimately lets you move in all 3 dimensions and interact in all 3 dimensions. Outside of space sims, name a game before Doom that had both height and depth in its actual gameplay. Maybe some space sim like games, like Tanks, but that's about it.
And I've never heard of Hovertank, but Catacomb Abyss predated Wolfenstein.