Mhmm, I understand what you’re saying. One factor that came to my mind just now (sitting in the waiting room for my doctor lol) is that, as a kid, I didn’t have that sensory-overload level of games I could be playing. At first, my family had a PS1 with Spyro, Tenchu, Dead or Alive and Tekken on it. I think that was it. Or at least those were the only ones I can remember off the top of my head. For a couple years I only was able to play these four games (it was a modified console, so it could only play burned discs, on top of it). That together with the fact that, as a child, I didn’t need to concern myself with anything mentally super taxing while playing, probably resulted in me just devoting enough time into the games to find secrets/routes I would run past now. Maybe it’s similar for you?
It’s a bit rough around the edges, but you (or someone else) might enjoy Genesis: Alpha One
You fly a space ship (well, mine usually look more like stations that can also move), across different life-infested solar systems. The main gimmick is that you build the station yourself out of different modules.
So when your scientists come back from planet surfaces, with some spores on their suits, you might find pockets of ewww hiding in the vents of the station you made yourself. You have/unlock multiple times ways to make sure that the infestation stays relatively isolated to, say, the landing bay. But even with those, you’ll find yourself doing a lot of first-person vent-crawling to figure out where that disgusting crab-thing just came from.
Plus, it’s a rogue-lite with some permanently unlockable progression. There are multiple player factions you can unlock and there’s a NG+ mode, but I found myself not replaying it too much (even though my one played campaign was quite fun). Still, I sunk a good 16-20 hours into it, I think.
Absolutely UT 2004. I reinstalled it a couple years ago and it holds up quite well. Especially the Onslaught (a classic Battlefield-like) game mode is still so much fun. And the bots aren’t just braindead idiots. They really want your guts, so you don’t need other humans for a good time. They even insult you over voice chat!
I will check out Tunic, once I’m done with one or two more games that I have currently installed, but on your hypothesis of games being made with internet knowledge in mind or them just generally being harder: Most games today are (or can be at least) much more complex in their systems than previous generations. Take X4 Foundations for example. It has a properly living economy. As far as I know, no ship and weapon just get spawned in without someone having mined and processed the ressources to do so. The game keeps track of thousands of ships over a volume of tens of thousands kilometers. And since you can mix and match every ship with a huge amount of equipment options, you can’t just point at a single thing and say “If I do this, I win.” But it also has some obscure systems, I can’t deny. For example that you can use EMP bombs to steal building blueprints, so you don’t have to buy them.
So while some games absolutely are made with the intent that only those who use the combined knowledge of the internet have a chance at experiencing every secret (looking at you, Five Nights At Freddy’s), most games are just harder due to the tech that makes it possible to do a certain thing in the first place.
On the other hand, I remember Morrowind being mentally difficult in some respects because there are no quest markers and very little other help aside from what you figure out on your own and what gets written in the in-game journal.