Learning is easy. Most idiots will adjust behavior to clear negative feedback. That's part of my problem with the "fail fast and fail often" mantra: it encourages a less efficient way to learn; the quickest way to get good at something is still to get it right the first time and never look back.
I think good teachers and good games can evoke that; by carefully constructing context, you can guide intuition toward the right answers without having to go through the (fairly jarring) process of feedback and adjustment. Any neural network can adjust appropriately based on how wrong it was; part of the real beauty of human cleverness is in figuring out which data to connect, and beautifully clever teachers and games are the ones that make you smart just by teaching you in just the right order.
If you want one of those game worlds that seems endlessly intricate and explorable, part of the key can be in guiding attention away from the things that shouldn't be examined too closely. Things retain a lot more detail if they aren't observed. Dead-end paths don't have to look like dead ends; as long as they look less appealing than some other path, they won't be explored first. And if the path explored first keeps bringing up new interesting branches, it's very easy to never think back to that one fork in the road.
One big barrier to this is an anxious completionist mindset: if the player feels like they need to get every coin, they'll intentionally go against all their intuition in order to explore everything before they keep going. And it can be really easy to make players feel that way: if I don't know that I absolutely definitely don't need to bother getting more coins, I'll probably go looking for them. In the absence of evidence, I assume more coins will be noticeably better, so if I have any, I'll look for em all. (It's not true for all players, of course).
But even if you want to have that path explored, even if you really want a big intricate game world with lots of side paths and hidden treasures, you don't want a player's first play to feel crippling. They'll be grateful that they seem to be going the right way, even though they don't quite know how (they must be in the zone!) It helps give the player that relaxing, optimistic feeling that good games cultivate: we love to feel like we don't have to go through that harrowing feedback and adjustment. We love to feel like we go down the deep, dark corridors only because we chose to go looking for treasure (not because we really didn't know if we were supposed to!)
I'm playing with the idea that in the perfect game, you never actually screw anything up, not because it's impossible to do so, but because your intuitions are so carefully guided that you manage to understand exactly the right decision at every turn.
That's the extreme; obviously failure happens. Gunpoint had a great mechanic where, when you died, it would rewind by increasing time increments until you stopped making the same mistake. This is a fantastic way to minimize how painful adjusting to feedback is: there's nothing worse than fighting through 1000 grunts before you can fight Ifrit again.
I'm really a fan of the idea that ultimately, a game should allow the player to do whatever they want. Sometimes that's different from how they'd self-report, though: you might say you want to win, but you mean you want to win by getting good at the mechanics laid out before you. But if you really do hate critical hits, you, as the player/user/dev/everyman, should be able to turn them off. The player should be allowed to explore all the dead end paths, but if you don't really want them going there, craft your environment such that they don't really want to go there either. If they never do, then all those forks in the road will forever hold infinite amounts of untold mystery.
I'm always a little afraid when somebody takes control of somebody else's experience "because they know best". But teaching is an interesting exception: the imbalance in knowledge or skill is an intentional part of the relationship between student and teacher, and in that case, it does make sense for a teacher to assume they might know better than the student, with regards to what the student means, what they want, or what they can do.
I'm a big fan of what I'm calling positive play (until somebody stops me): give the player everything they want.. but not necessarily what they say they want.
