I had never really played any "open ended" games before it; sometimes I would just load up the game to run around, with no goals of collecting any stars or making any progress or anything. The platforming controls were fun even when there wasn't any specific "goal", and to a six year old kid the worlds felt huge.
As a cynical grownup who more or less knows how to write software, I now know that a lot of the "gigantic" feeling you'd have in N64 games was smoke and mirrors, but I didn't as a kid. It felt like if I just swam to some yet-unexplored corner of Jolly Roger Bay there would be something waiting for me. It doesn't hurt that the music is actually really good (particularly in Jolly Roger Bay).
Without hyperbole, as a thirty-something now, I've probably played through the game around thirty or forty times; I have most of the stars pretty thoroughly memorized and I can get an "any%" completion in a couple hours. I will still load the game up every now and again on my MiSTer. Despite being one of the first big 3D platformers, I still think it's one of the best.
https://archive.org/details/GoldenEyeXBLA
It is also one of the few "remasters" that let you toggle the original graphics on the fly. (Mapped to R1 on the gamepad.)
Similarly, old shooting games before doom sometimes had no dedicated control for strafing. They didn't seem to realize how important it was. But it's bad.
If you boot up Goldeneye and Perfect Dark in an emulator, you can set them up with the control scheme that uses the C buttons as the second "stick" and remap things to give yourself near real dual stick controls like in modern shooters, and it's night and day. The games stop feeling clunky. The autoaim becomes actively harmful.
I did this once to my brother in multiplayer and there was absolutely nothing he could do to combat my fluidity of movement. It was trivial to just circle strafe him.
Having the two axis of a control stick do radically different things (turn vs move) is terrible. It's like playing a racing game where pushing up on the stick is your accelerator. It's just hard to use that input in a controlled way while also trying to deal with the other axis.