They're not insane like Myst puzzles (good grief, later in the series they get to be practically impossible
Exile was easy. Edanna practically played itself, and Voltaic wasn't really 'hard' outside of one of the gauges you had to fiddle with behaving in a bizarre manner (and initially it was bugged, iirc). Amateria actually required thought but it still wasn't hard.
The only Myst puzzles I found particularly overly-difficult were the Spider Chair Organ thing in Myst 4, the pyramid puzzle from Kadish Tolesa in Uru, and the firefly thing in Uru. The Kadish Tolesa puzzle I had a problem with because it's solution wasn't really in line with the broader theme of what was going on in Kadish Tolesa (the final puzzle in that age, however, worked with the theme with aplomb). The firefly puzzle involved platforming and having an inventory object in a nominal sense, neither of which are even remotely Myst-like. Also it couldn't really be solved by experimentation because the fireflies only came out at specific times and even then you had to pretty much luck into getting them to follow you, otherwise they just looked like scenery.
I was sort of disappointed that most of the Myst games returned to the style of having discrete ages like in Myst, instead of having a single continuous gameworld where all of the puzzles ultimately fed into eachother.
wrt Zelda, some of the stuff I got stuck on:
- Fire Arrows in OOT, because seriously that made no sense.
- Some of the places you had to teleport between the light and dark world in LTTP, because there's not much indication that you need to do that.
- The bomb plants in WW. I think it was when you had to water them? There was no precedence for them NEEDING water so I got stuck.
- Something with the Bigoron Sword Quest in OOT though I don't recall what.
- I also recall using a walk through on the balloon popping thing in TP then feeling like an idiot because that actually had a really obvious solution.