Approval of God: Though he had no direct involvement in its creation, Silas S. Warner enjoyed Wolfenstein 3D and congratulated id Software on their work.
Banned in China: This game wasn't authorized for sale in Germany, for obvious reasons. In fact, this game was responsible for restrictions against the depiction of swastikas and other Nazi symbols in video games in Germany, despite its clear and unambiguous anti-Nazi stance (the fact that the game was hugely popular in Israel, whose people have reason to be even more sensitive about depictions of Nazi Germany, tells you all you need to know about its depiction of the Nazis). After years of mounting backlash, and in recognition of the advances in content warning labels and other classification systems, Germany lifted the ban in 2018.
Cowboy BeBop at His Computer: The SNES version's boxart design seems to have the assumption that the game is about a Rambo-like commando in The Vietnam War who uses post-WW2 weaponry. It comes across like the game is realistic or even a Tactical Shooter. The game's title screen is much more accurate, with a picture of BJ firing a massive minigun.
Creator Backlash: John Romero has said flatly that Wolfenstein 3D's level designs are boring aesthetically (there's only so much you can do when your levels are invariably made up of cubes of the same size put together) and that no one enjoyed making them.
"Call Apogee, Say Aardwolf!" It's still there (E2M8), if you know how to get to it.
In the PS3 version of Wolfenstein 3D, the Pac-Man ghosts are removed from E3M10, possibly due to copyright reasons, and replaced with Hitler Ghosts, taking out the fun quirk that makes the secret level famous.
The GBA port has music in the ROM itself, but it does not normally play. It is possible to get the music working on emulators, but not with a standard cartridge on real hardware; even then, it does not play properly as the music player code was left unfinished for whatever reason.
God Never Said That: For years, it was thought that the release of Super 3D Noah's Ark was a big Take That! to Nintendo. According to the rumor, id was angry about how Nintendo had censored the SNES port of Wolfenstein 3D. So they outright gave the source code to Wisdom Tree and helped them get the Noah 3D mod running on the SNES (the SNES already had the engine operational, the game was basically just a mod, not much different from the many Doom mods you can still find today). It seemed as though the game was basically one gigantic middle finger from John Carmack and John Romero to Nintendo's SNES-era censorship policies. Wisdom Tree eventually stated the whole thing was bunk and they paid for the license to use the Wolfenstein engine like everyone else, which id seconded; while the game was unlicensed, that was only on Nintendo's end as far as actually releasing the finished game on their console.
Money, Dear Boy: The real reason why Super 3D Noah's Ark exists: Wisdom Tree paid id pretty good money for the Wolfenstein 3D source code.
Port Overdosed: But of course. Wolfenstein has been released almost as many times as Doom.
Promoted Fanboy: The developers were all fans of Castle Wolfenstein, and opted to remake it. When they found out that Muse Software was defunct, they wasted no time in securing the rights to the Wolfenstein IP and started working on it.
The game was originally intended to draw a lot more stealth elements from Castle Wolfenstein. For starters, hiding corpses. This idea was eventually scrapped because John Romero felt that it slowed down the game too much, and the gameplay shifted to emphasize fast-paced action.
Even before that, it was going to be an alien-themed game with the most awesome title ever: It's Green and Pissed!
E2M8, with the secret-wall maze, has a room with a graphic reading "Call Apogee - Say 'Aardwolf'". This was meant to be a condition for a contest, if it weren't for the (very swift) small-time coders who came up with their level editors to find the graphic with little effort.
Wondering about those letter codes at the high scores? That was part of a cancelled contest too.
Rise of the Triad was originally a sequel to Wolf 3D, which can be seen in the finished game with things such as its arsenal (all the traditional firearms are WWII-vintage at the latest) and the appearance of several enemies (though the story claims their clothes are from Korea, they just have that sort of look).
. This would further be reinforced in Wolfenstein II: The New Colossus.