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.
YMMV: Star Fox 64
Anti-Climax Boss: Andross, his attacks hurt, but are easy to avoid, and a hyper laser, which a player can get from corridors along the way to the fight, can kill him in seconds. The robot head you fight at the end on the easy path is downright pathetic, its charge attack is a joke to avoid, and that's its only attack, and most bosses you fought before this thing take longer to kill. The only challenge a player might have is with Andross' brain.
God Damned Boss: Andross' brain does tight circles in All-Range Mode making it fairly annoying to line up a good barrage of shots against it, and careless maneuvers can cost quite a bit of health. The Sector Y bosses are also in All-Range Mode and move around a lot.
Hilarious in Hindsight: Slippy mentions that the Arwings can withstand temperatures up to 9000 degrees. The North American release was released before Dragon Ball Z and its infamous "Over 9000!" meme.
Memetic Mutation: "Do a barrel roll!" and "Can't let you do that Star Fox," might be the most famous, but as the YMMV for the whole series points, the whole game is a Fountain of Memes.
When you die and your teammates are still there, they'll give a big NO!!!!!!. If you die alone, though, you're treated to Fox's grisly last moments where he screams. Pretty horrifying for young first-time players, to say the least.
Andross can be quite the scare given how he suddenly pops up, he's a freaking giant head floating in the air, and one of his attacks consists of inhaling you, chewing up, and spitting you out. The music and the grunts and laughs he makes don't help either. It gets worse if you take the Hard route. Once Andross is "defeated", you get to fight his fucking brain and floating eyeballs! The music playing in the tunnel leading up to him is no slouch either, and the tunnel being different in Venom 2 helps add to the suspense.
Nightmare Retardant: What's the first thing Andross does when he's reduced to his brain form? Make a pun.
The Golemech, the penultimate boss on Venom's easy route. The pillars that come out of the wall can be incredibly hard to dodge, and it gets even harder if only one part of him is left to attack.
Sarumarine, the boss of Zoness. He can only be damaged by bombs until all his parts are off, it's easy to attack the parts in the wrong order, and his morning star can easily clip your wings.
This is lessened somewhat by the fact that he constantly spews bombs for you to scoop up and use against him.
The battle with Star Wolf on Venom 2, generally regarded as the hardest fight in the game. Much harder than on Fichina/Bolse. Continuing Is Painful, indeed, as your hyper lasers can quickly down two of the fighters before Wolf starts annoying you. The AI for the whole team is much better than before, they're all faster, and bombs and charges won't hurt them. The encounter is also much more difficult if you're missing team members, since Star Wolf members go after you if their corresponding wingman is down.
Taking out the Macbeth boss by way of switching the tracks so the train runs into an ammo depot. To do this, you need to hit 8 switches. Simple enough, right? Except 2 are on the left of the track, which doesn't sound like much of a problem until you realize that you'll be focusing on the right so much (due to the 6 other switches) that you're almost certain to miss them.
Taking it out directly is even worse. For starters, it's an airborne boss and you're in the Landmaster. So you'll constantly be getting hit by it's many ground-based attacks that you won't even notice half the time because you're too busy just trying to hit the damn thing. Most of those attacks are pretty damaging too. Trying to reach the end of the track is even harder because you'll need to survive a long time (it's not called the Forever Train for nothing) without any pickups lying around, plus it's a bad thing to do anyway, you just lose your ship and have to try again. The fact that fighting it is the "easy" route just throws salt in the wound.
Sector Z: it's an Escort Mission of sorts, where you have to protect the Great Fox from incoming missiles. It's swarming with Invader-III fighters (which have the best AI of all the enemies in the game bar Star Wolf or the Bolse Fighters) which means you'll constantly be listening to your wingmen calling you for help and it has just enough junk on the outskirts to ensure that you'll almost certainly crash into something and rip off your wings. Worst still is that if you're going for the medal, your wingmen can actually steal your points if they're the one to land the last hit on the missile: and if you come from Zoness you'll have to contend with Katt kill-stealing from you as well, and then saying that you owe her one for it.
Aquas. There's only one way to get to it, the level is slow (and underwater) and due to how the Blue-Marine's missiles work (locking on to the first target your crosshairs hits, and you can only fire one missile at a time), it's difficult to get the required 150 hits to earn the medal for the stage. On the other hand, it's significantly easier to get a high score than Katina or Fichina, both of which are all-range missions.
That can be (somewhat) remedied by constantly barrel-rolling while spamming your lasers and unlimited (for this mission) seeker missiles/bombs. With a little skillful steering, you can breeze past this mission. Can't guarantee that it won't hurt, though.
Fichina's problem with getting a high score is an actual lack of targets. It's arguably the easiest medal in the game due to the fact that the necessary score is so low, beating Star Wolf gets you almost all of the hits you need.
Solar. What can you say about a level that is so hot, your energy is constantly decreasing? Even getting your health boost mid-level won't help, as it'll keep going down. By the time you get to the boss, you'll be hanging on with half health or less, and it's got screen-filling attacks...
Venom 1. Even with the battle against Star Wolf on Venom 2 being, as mentioned above, the hardest in the game, it's still arguably the easier of the two paths, thanks to a combination of enough enemy laser fire to push the game into borderline Bullet Hell range and Malevolent Architecture that often pops up out of nowhere (sometimes just erupting from the ground, but other times using the same technology as the Area 6 boss to teleport in from hyperspace) and ensures that the usual method of dealing with enemy laser fire won't work. Also, in Expert Mode, Venom 1 gets way more ships, and way, way more lasers being fired from those ships, while for Venom 2 Star Wolf's skill level is already maxed out and not changed much for Expert mode.
Titania in every way possible. The stage itself isn't too bad, even though for some odd reason several dangerous machines are trying to attack you in the middle of the desert. What makes this stage annoying is that you have to use the Landmaster, which some players hate. The only reason why you even go to this god-forsaken planet is to save Slippy. And unlike Macbeth, Titania's boss doesn't give you the option to earn fifty hitpoints, so getting the medal is frustrating. Finally, going through this stage locks you out of going to Area 6 and, by extension, the backdoor Venom route.