These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
With the All Guns cheat on, if you switched your weapons back and forth in a certain way, you could dual wield two different guns, which could have hilarious results such as using a rocket launcher and a grenade launcher, or a laser gun plus the watch laser to make Bond look like he has three arms!
A+B to instantly detonate remote mines. No watch required. Basically turns them into smart grenades.
Misaimed Fandom: The Goldeneye team seem to have liked Boris enough to make killing him during Control a mission failure condition (barring certain devious trickery), with Natalya refusing to reprogram the satellite if Bond shoots him. This despite that Natalya's first reaction to meeting him at this point in the movie was that she tried to kill him, due to his complicity in the Severnaya attack, the death of her friends, and the fact that she was repeatedly nearly killed and possibly almost raped as a result of Boris' dickish associates. Um, zany!
Scrappy Weapon: The Klobb. It says something when, in Goldeneye: Source, it is a starting weapon in all sets it is in and lowers the Mercy Invincibility timeout (making rapid fire more useful), and people will still charge each other with melee weapons before even considering to use it. It has poor accuracy, a small mag, and the lowest damage per shot of any weapon in the game. On the highest damage settings, the Klobb is the only weapon that will not kill you in one shot.
Seinfeld Is Unfunny: In 1997, this game was nothing less than legendary, and singlehandedly kicked the term "Doom clone" out of the Official Gamer's Lexicon. Now, every other console FPS has not only copied its innovations, but improved upon them.
Stop Helping Me!: Natalya will accidentally shoot you if you get in her line of fire during the Jungle stage. On the other hand, you can also trick Mooks into shooting each other as well.
Control. Dear lord, Control. It starts with cleaning up the first room to make way for Natalya, and for each soldier in it there's a sentry gun ready to mince you. You have to be more than stealthy if you want to make it relatively unscathed. Then there's this room with the sentry guns aimed at the door (as well as the soldiers facing it), so opening it up might not quite be a good idea. And then there's saving Natalya's bacon while she hacks into the computer... particularly annoying are the guys who randomly appear directly to her left and right and immediately proceed to start emptying bullets into her, while you'll inevitably be tied up on account of the multiple shooters coming down the various stairs. It's also one of the longest levels, usually taking about 15 minutes to complete.
The Caverns is even longer, and the Aztec is probably the most difficult of all, especially on 00 Agent. Basically, if one of the enemies in your starting room throws a grenade, you lose. If someone gets a lucky shot, you lose. If anything is other than perfect in your run, YOU LOSE.
Egyptian is an aversion; it's impossible if you don't know how to do it, easy if you do.
Cradle is also a pain. Never-ending mooks are the real final boss as you play cat and mouse with Janus. You can die before even making it up the first ramp on 00 Agent; due to the system's poor resolution, you will see the enemies as a couple of pixels while they shoot you with perfect accuracy.
Train is extremely frustrating because it involves fighting your way through several cramped cars full of mooks while surrounded by exploding crates, and then there's an very difficult Hostage Situation which gives you about two seconds to kill Orumov before he shoots Natalya. Then you've got to wait for her to work on the computer while a timer counts down to an explosion. You always have about four seconds to escape from the car before it explodes and get Natalya out too, while yet more mooks are waiting for you. It's just too easy for things to go wrong and make the entire level a waste.
Not if you shoot Xenia along with Ourumov - this gains more than enough time for her to crack the password and cautiously exit through the hole to take out the last guards.
Xenia actually turns into a joke if you realize the limitations of the engine; Xenia can only shoot across the bridge if the player is standing at the other end. By simply standing off to the side and shooting diagonally across the gap as she makes her sprint, she'll very likely be dead before she even makes it across. Not to mention that you can just throw all your remote mines on the bridge and kill her instantly as she crosses it. Artificial Stupidity indeed.