- Critical Research Failure: The original manual for Castle Wolfenstein describes the firearm that the player is given at the start as a "Mauser M-98 pistol fully loaded with ten bullets". The real-life Mauser M-98 was a bolt-action rifle with a five-bullet magazine (ironically, the soldier depicted on the game's cover is carrying a rifle, but no rifles are seen in the entire game). It is possible that the game developers confused it with the C96 (a Mauser pistol with a 10-bullet magazine). But by World War II, even that gun was largely discontinued by the Germans in favor of the Mauser HSc, Walther P38, and Luger P08 (all of which had eight-bullet magazines).
- Demonic Spiders: The SS Stormtroopers in Castle Wolfenstein are notorious for showing up when and where you'd least expect them, and are very tough to kill for anyone that doesn't have a grenade handy. They will also pursue your character throughout the castle if you don't kill them.
- Sequel Displacement: The popularity of the FPS saga Wolfenstein has overshadowed the originals to the point that many gamers don't even know the series started off as a Stealth-Based Game.
YMMV / Castle Wolfenstein