Wondering if you folks could work your magic to help me identify a 90s first-person shooter based on this list of my not-so great memories of it:
Timeframe, region, and technology:
I played this game in the US in the 1990s. I don't remember purchasing it, so maybe it was shareware or part of a shareware pack?
I cannot recall any in-game language, either as text or audio, but I also don't remember the title or manual (if there was one) not being in English, so the language was almost certainly English.
I played it on a Windows machine, so it was either an MS-DOS or Windows game.
I think the computer I played on did not have a graphics card; if so, the 3D effects were all in software. I know that they were pretty low-res and not very impressive compared to what came out near the end of the 90s. The geometry was textured, not in solid colors, but the textures were visibly pixelated—quality was on par with or maybe a little worse than Descent as mentioned in the comments. I think the lava texture (see below) was animated.
There was variation in floor height within rooms, so the engine had at least that much sophistication.
I have a vague recollection that the rendering of enemies did not mesh perfectly with the rendering of the surrounding space. Though 3D-shaped, they might have been prerendered, which meant that they couldn't rotate smoothly as they player looked at them from different angles.
I also remember no room-over-room, so maybe these clues point to the game being a Doom WAD?
Story:
I am certain that it was some kind of sci-fi game. There were no human or humanoid enemies that I can recall (with the loose exception of one enemy who was a floating face). I don't believe that the player character was humanoid either; there was certainly no rendering of a human arm holding the player character's weapon. (Unfortunately, I can't recall if the weapon was visible on screen or not.) Everything had a mechanical feel about it. There was no hint of magic.
I think the game was set in cyberspace and the goal was to eliminate bugs or viruses. Shooting was a metaphor for debugging, I think?
Levels, enemies, and player character:
The setting was definitely a series of indoors, mostly enclosed spaces, not too brightly lit. It might have been divided into levels since I remember clear one-way transitions between regions. (I can't recall any loading screens, but I'm a lot less confident that that part of my memory is accurate.)
I remember the first enemy being a floating gray spiky polyhedron, like if you took a many-faced platonic (or maybe archimedean) solid and attached a tall polyhedral cone to each face. I believe that it turned either red or blinking red when aggravated and could attack by ramming the player with its spikes.
I remember a very early (first?) room being a large open space that led to a split into three corridors that then reconverged at the room's exit like this:
⤤↑⤣. I'm pretty sure that the there were two of the spiky gray balls loitering at the end of either side corridor so that you could clear them from the sides, but if you charged down the middle you would find yourself flanked. After further thought, I am pretty sure that there was something like stained-glass windows and/or organ music in this room that, in combination with the dark-gray walls, made me think of it as a cathedral. I have a vague recollection that there was an item or items in a recess in the wall as part of the cathedral area.I remember another early room that had what I think was a pool of lava (fire-colored floor and walls, possibly a translucent texture for the pool's surface?) separating the player from the aforementioned floating face enemy, which I think had a devilish appearance and/or a malicious laugh. There was some way to freeze the lava, making it turn blue and safe to cross—I think shooting down the face from afar.
I remember that right after a one-way door at another point early in the game, the player found themselves at a T intersection and that there was no clear guidance whether to go left or right—at first glance the situation looked symmetric.
I remember a later space that felt like cubicle-farm geometry. I think the room had a large square depression in the floor broken up by walls, but those smaller "rooms" did not have any ceilings.
Game mechanics:
The player character's movement was bound to a fixed hover above the ground level; you could turn but not tilt, and you could ascend or descend only with the terrain. I think that there was some "coast" to it, and you would keep floating along for a while after you released a movement key. I'm pretty sure that it took me a bit to get used to aiming while coasting.
As far as I can recall, all enemies were defeated by being shot at. Unfortunately, I don't remember very well what that looked like (I would guess that, at the start of the game, the player character could only fire single shots, probably with some travel time, or else the early enemies wouldn't have been a challenge), but I am pretty confident that the player character had infinite ammo.
The player character must have had more than one hit point because I remember finding out about the danger of both the spiky balls and the lava by taking damage, not by getting a game over. But it also couldn't have been possible to tank too many hits because I remember having to be careful. Less certain on this, but I think that I originally got through the lava room by crossing the lava and only later figured out that it could be frozen.
My memories of the early game are clearer than of the later game, so I suspect that if the player character died, you would have to restart from the beginning.
I think there were items that could be picked up by running into them, but if so, they were rare.
