Placement of rooms and monsters is ridiculously quick and easy, but setting the logic of how they spawn, behave, where ammo comes from and what makes a level end is far more involved. I have had much bigger and more complicated versions of Cacovision, lost to the winds of time because I didn't save often enough, but I'm just not up for repeating all my work so you'll never get to see it. However, it took me at least twice as long as it should have done because running a PC with an eight-year-old motherboard has become an increasingly doomed endeavour - no pun intended, I'm afraid - and it now restarts itself every quarter of an hour when playing DOOM.

'Cacovision', which you can find and mock by searching for DQR6PKCM in the DOOM SnapMap menu, took me several hours to create. I'm quite pleased with it, because I am 13 years old again. Which, naturally, required a red keycard to access. Because DOOM instantly makes me revert to being 13 years old again, my first SnapMap was a tiny room filled with 30 Cacodemons, with a boss Cacodemon with 1000% health waiting in a room just beyond it.

Doom snapmap guide extraction