I've only played Star Fox 64 and the original on an emulator.
But on 64 I unlocked Advanced mode, unlocked characters for versus, and got all but a couple of medals in Advanced mode. I think the ones I never got were Solar, Titania, and probably Sector Z. But I haven't played in ages, so I don't think I'd be anywhere near as good as I was that one summer when I did all of that. I think my high score is in the 1300's.
Hmm, My high score was 1876 (i still have the cardridge

), I had all the medals in expert mode, and remain undefeated in the multiplayer after hundreds of matches.
StarFox 64 was in my opinion the best arcade space shooter there ever was.
The only thing I never figured out how to do was how to score 277 hits on Venom(I managed 228 by blowing up Andross's two eyes simultaneously with a Nova Bomb)...Even Nintendo Game Counsellors didn't know, but I saw a screenshot of that score in Nintendo Power Magazine eons ago which means it can be done in a legit manner (but I still can't figure it out)