> Chasm: The Rift

I might be misremembering but I thought it was more of a Doom-style engine with 3d models instead of sprites for the entities, rather than a full 3d engine like Quake.

It was definitely something unorthodox - I remember being confused about how it actually worked.

The first time I played, I thought "It is just like Quake". Then you start to notice that the levels are pretty limited - it is all narrow corridors with rare small chambers and open spaces, no steep elevation changes, no rooms above rooms... Kinda like Doom. But then, father's examination shows sloped surfaces, shelves and bridges - stuff the Doom engine can't do.

Maybe, for level geometry, it is closer to portal rendering engines like Build. Still looks pretty claustrophobic even compared to Doom and Duke Nukem 3D. I feel the Chasm level designers could've got more variety from that technology, but again, maybe that was some fundamental limitation. Or maybe it is just like FPS were designed in the mid 90s.

Monsters, items and weapons are fully 3D, though. With dynamic lighting!