You never heard of Breathless Amiga clone game of DOOM?
It had all features of DOOM, including textures, shades, light effects, jumps, and on basic Amigas it could be even shrinked in pixels down to 160x120 to grant playability, or enlarged if you had had CPU with muscles...
That's not true though, now is it. Breathless had a very simple orthogonal map structure that had more in common with Wolfenstein 3D than Doom. In fact, I'd say from an engine perspective it essentially was Wolfenstein 3D with variable height floors and zone lighting.
Doom, OTOH, had a complete 2D BSP based engine that allowed a plan view of the map to have any arbitrary geometry.
What Breathless had going for it was the fact it was one of the first, if not the first game of it's class to use C2P rather than chunky display emulation. In the long run, that gave it a significant advantage on faster machines.
On accelerated Amigas Breathless game make use of more horsepower speed and it could even recognize graphics cards connected to amiga AFAIK...
Also to gain speed you could change textures from 1x1 pixels to 2x2 or 4x4 or even remove it and revert to solid rendering of surfaces without any textures.
Breathless was a real masterpiece but its existence was just barely known amongst amiga users due to the fallen of Commodore.
Alien Breed 3D 2 was technically way more advanced. Like Doom, it allowed for arbitary geometry (though it required you to do the job of a BSP tree generator when creating levels, manually subdividing your map into convex zones) and unlike doom, it allowed two levels of floors in the same zone, allowing the creation of bridges. The use of vertex illumination (goraud shaded) and support for polygon models was also more advanced. Lightsourced sprites were also supported. The water refraction effects were peerless on the amiga.
The principal problem was that it was also very, very slow.
