I finished playing this map and… Wow! Impressive level design. They don’t make them like this anymore.
If you haven’t played it, you definitely should.
if you’re using GZDoom, open the console and type “map e1m8” to run it
Oh man that was fun!
Now I’m addicted to DOOM again! 
215KB? Even mobile app nowadays are bigger than this.
Just to be clear, I have been playing games since 1980s, and this size is normal during those days… (it fits into a quarter of a 3.5 floppy disk)… or just barely enough into 5.25 disk.
Doom was my first virtual love 
Mine was System Shock 1…
And I still am in love with it! After all these years! 
I played that game very often too.
Last time is not long ago, perhaps two years.
That was a real good game, with real good gameplay and even without realism or overuse of gore or very detailed limb cutoff or zombies…
Good example for very well game/mapdesign/gamelogics, when you ask me.