For those who don’t know, Doom 64 was suppose to have a very well-hidden easter egg in the level ‘Breakdown’ that only the developers knew about. It was first mentioned by Doom 64 designer Tim Heydelaar in the Doom 64 developer interview. Unfortunately, this easter egg never existed and only remnants of triggers and unused scripts exist in the map. While these items are still in, they do not do anything and most of the data is disabled/incomplete when the level loads. Even if these triggers were hacked to be initially enabled, they still do not do anything.
As mentioned in the interview, the player had to ‘use’ several walls in a specific order to trigger the hidden message and no ‘oof’ sound is played when the player successfully triggers them.
Below is the overview map of Breakdown. The colored arrows are explained below:
* Yellow Arrows – Walls flagged as ‘secret’ which prevents the player from making the ‘oof’ sound when pressing use on it. Unfortunately any triggers or specials associated with them are removed. Tim claims there’s only 3 of these ‘switches’ that you have to hit but I’ve found more than 3, though he’s correct about one switch in the BFG secret and the other in the red key room.
* Red Arrow – While hidden in the automap, there’s a small inaccessible room that contains several triggers that’s triggered on level start (in Doom 64, a linedef with a tag of 999 is automatically triggered on level load). These triggers call several scripts that never does anything (explained further below).
* Green Arrow – This trigger is inaccessible from the player and is flagged to be triggered by walking over it. Oddly, the script associated with this trigger enables itself.
In addition to this, there are several unused scripted events that’s never referenced anywhere on the map, though some seems to be linked to the script that’s triggered on level load.
* Script #15 – Spawns darts, though none exist in the map. Could be leftover stuff from an earlier revision. It’s assumed that this level used to be a ‘castle’ themed map since there are some unseen castle textures scattered throughout the map.
* Script #16 – Never used anywhere. Enables script #25, which is not present in the map data at all.
* Script #17 – This script is automatically activated on level load. It disables scripts #17, #20, #21, #22, and #23
* Script #18 – Enables script #18 (weird)
* Script #20 – Not used in map. Enables script #22
* Script #21 – Not used in map. Enables script #23
* Script #22 – Not used in map. Enables script #24, which doesn’t exist in the map data
* Script #23 – Not used in map. Lowers sector floor tagged #27. There is no sector in that map that has this tag. It’s assumed that this is where the ‘secret’ is revealed.
Majority of the scripts listed seems to be responsible for the order in which the switches had to be triggered, but several scripts and a tagged sector is missing in the map’s data so we will never know what this secret was suppose to be.