Individualised

I don't know why there's any question about this being the original DOS version. The 3DO version is derived from the Jaguar version; it's impossible that a prototype version would have looked like this. The soulsphere giving armor is interesting. At first I thought this might have been pre-release footage of DOS Doom (it almost looks like a cut IWAD level) but if you look closely it says "You got the mega armor", so I think it's just a reskinned mega armor. The HUD at the pre-rendered sequence at the end is the most interesting part. I think this is from a pre-release version of Jaguar Doom, because it's vertically extended in the right ratio in order to accommodate for 320x240. There's a prototype of 32X Doom with a very similar looking HUD. No idea what it would be doing here though.

Many of FastDoom's optimisations are through x86 assembly and would be of no use to a port for another architecture.

This early footage of Donkey Kong Country 2 uses a different music track for the mine levels.

DOOM64-RE is far from vanilla - it has additional features and changes, so it wouldn't surprise me if these are actually implemented there. I'm not sure why this was done like this, new features are a better fit for a source port or mod (like Merciless Edition which is based on it). There is a lot of value in having a clean reconstruction of the original Doom 64 code that I feel is being overlooked. At the same time this type of reverse engineering can be very difficult and time consuming so I don't ask for or expect anything at all.

EX-Plus has it now, but my understanding is that it originates from the remaster (which is based on EX).

Thanks! I've edited the page with my understanding of this information. Would this be correct?

For the purposes of correcting this page, is this documentation otherwise accurate apart from flags 10-12? Is flag 4 present in the vanilla game?

I hate to bump this topic again but I found yet another example; this time on a non-Doom IWAD (Snap the Sentinel). I've never even intentionally enabled strict Doom floors on that game (separate config from Doom) - are strict vanilla floors enabled by default on GZDoom? This is starting to trip me up over and over and I'm surprised more people aren't reporting this issue if this is a default setting.

On Doomwiki's "Thing" page, it has documentation for the format of THINGS lumps for various id Tech 1 engine games, including Doom 64. I noticed that it lists Doom 64 as having multiplayer-related flags for actors (bit 4, 10, and 11). Obviously vanilla Doom 64 doesn't have multiplayer, so I'm wondering if this section is mislabelled and corresponds to a source port, or if these flags are actually present in vanilla Doom 64? I can understand the "not in singleplayer" flag being present as that originates from PC Doom but the others are new, and don't particularly make sense to be there unless they're development leftovers. I don't have any vanilla Doom 64 editing utilities on hand, so I can't test if these have any effect there. Doom64EX-Plus's actor flags enum in doomdefs.h does reference these, perhaps they originate from there? They're also in GEC DOOM64-RE, but that section of doomdefs.h seems to be directly copied from EX (same comments and even has the nightmare flag), and that decompilation is far from vanilla so I don't think I can trust it.

Doom 2 used sky floor exits before Ultimate Doom. E2M9 is a very weird level in many ways. It feels like there should be an interesting story behind it, but unless more pre-release stuff resurfaces we probably won't find out.

In Doom 1 the exit switch rooms were originally meant to be airlocks - the steel doors at the beginning of the levels had the same texture as the exit doors, and the exit switch rooms would have a locked exit door on the other side of the room: They actually forgot to retexture E2M3's beginning door so you can still see part of this there. I have no idea why they removed this, these screenshots are from a build only around a month before release. I'm guessing the other episodes didn't have them (how could you do an airlock in a hell level) so they removed them for consistency.

Chocolate Doom fixes this (and all other inaccuracies to the original executables that the source code release has), but I'm not sure where the relevant code is. If you're able to find it it should be a drop-in replacement however. I thought that P_ChangeSwitchTexture in p_switch.c might have been the culprit, but the code in Chocolate Doom seems to be identical to the source code release.

A lot of Plutonia's CWILV graphics are very poorly edited as well.

Both games were scored at the same time. 0.5 also tries to play a Duke Nukem II song as a placeholder (but it's not present in the .WAD). It seems that there is a lot of overlap between the two games soundtracks and I wouldn't be surprised if some tracks in one of the games were originally composed for the other game. There's a few Megadeth covers in Duke Nukem II which could have easily been one of the unused Doom soundtracks, and They're Going To Get You's melody is the Duke Nukem II main motif.

Sadly not. The Qtest1 ogre is a bit closer but doesn't have the horns or the axe. It does shoot nails instead of grenades which is interesting. Perhaps, but Sandy claims that his work was removed before release.