Yeah it was weird. Even cursor keys were better than the super old days of QAOP I love how each of those games did something new that moved things forward. Like at first you couldn't interact with the environment at all apart from doors. But in Doom, exploding barrels! Amazing. And then some game adds key cards, something adds an inventory, another game adds grenades and NPCs, it was like a global effort to perfect the fps and now it can be made into anything.They were so inventive, new gamers probably don't know you couldn't aim up or down in the early FPS. Wolf3d was completely flat, no hills, no stairs, no ledges. People played with left hand on cursor keys, right hand on the mouse, and the mouse only turned you left and right. Felt a bit like driving a turret, but it was still awesome. Unless I'm remembering wrong I think in Doom people still played the same way, cursor keys and mouse just did left and right. But they added some verticality to it with ramps and ledges, but you just had to aim left right with the mouse and the game would auto do the y axis if you got the x axis right. By System Shock 1 you could aim up and down but not with the mouse, and it wasn't even good keys. Again people still played with left hand on cursor keys which did forward backward and strafing so there were no nearby keys for look up/down. So I think they went with PgUp and PgDn.... Amazing game but damn, it's still a bit like driving a tank.
I remember playing Quake and having full mouse look with one hand, it felt great but it took some getting used to. It was also in Quake that I first saw people talking about switching to WASD. That took some getting used to as well, but it's better and more comfortable. The perfect control method sort of evolved with the games.
I recall most people actually played with keyboard-only, and various kinds of fucked up control schemes until WASD was standardized. Then later mouselook.
I do remember thinking System Shock was years ahead of other games though. And I remember finishing Duke3d and thinking that was the most fun ever.