24 MB. TWENTY FOUR MEGABYTES.

It just boggles the mind that such a fun 3d game is so small. I suppose it is because it was a shareware title at one point and thus needed to fit on cheap media. Still, I miss the days where you could get lots of quality game in one compact package.

Now I just need to get dosbox ported to my TI-84.

It doesn't matter so much that it is in a 3d space, all of the game models are simple polygons.

Being 3D does not necessarily make the game larger, it's not like you have to somehow store the extra dimension on the disc. The biggest space consumers are assets like graphics, models sounds and possibly levels.

The 3D models are very simple 3D shapes, even with no compression that takes up barely any space. The sound effects are pretty simple, the music is MIDI (stores the instructions for instruments instead of actual audio). There is also no sampled audio like speech and there are no FMVs.

That's huge, do you know how many 3.5" floppies you need for that!

Approximately 18 or 20 1.44 mb froppies.

Because it's fairly low-res 8-bit textures (by 2015 standards) of 256x256x1 (8 bits per byte) = 64k each, and each level vertex is ~96 bytes (assuming floats for each X, Y, Z which are 32 bits a piece x 3 = 96. Likely the coordinates are in fixed point (haven't looked at the source code in a while), knocking them down to 16 bits). Considering that the levels share vertices per each adjoined "sector" (each sector is an 8-sided box), each subsequent attached sector only takes 6 rather than 8 vertices. The enemy models are less than a few hundred polys (many are less than 100),
/Developer persective

In short, it was a lot for 20 years ago when max HDD size was maybe 540MB, making the ratio on that drive about 4% of it. In today's terms on a 1TB drive, that'd be the equivalent of ~40GB.

Thankfully not.
Descent came on 5 Floppys :D

I think the most extreme game when it comes to Floppies is the Amiga Version of Biing! (1995) that came on 17 Floppys (the Dos Version came on 11) and most of them were just used for the Intro video

It turns out that people were really good at compressing code.

No. Just,... no.

Oh, sure, it was either ARJ or ZIP compressed, but they didn't ask about the install disks, heh.

Most of the textures are only 64x64, 256x256 would be huge considering the target screen resolution was 320x200. It also ensured a maximum of one page fault per texture, for systems that had to resort to disk swapping (<= 4MB RAM).