It's not even clear that they're correct for the one example they go by. It's difficult to argue that "teaching" is essential to good design; to me it's just im

It's not even clear that they're correct for the one example they go by. It's difficult to argue that "teaching" is essential to good design; to me it's just important for on-boarding (that the "tutorial" stages aren't canned info-dumps and dreadfully slow, interruptive, and staged events that treat the player as incomprehensibly incompetent). I'm more inclined to the idea that good design is found in the ability to explore a ruleset, and the ruleset being interesting enough to justify exploring it. The art, music, themes and such all supplement the exploration of that ruleset (or even help define it). Good "levels" push you to explore the ruleset in ideally unintuitive ways, and lays the foundation for further exploration in future levels. Ideally, the game shouldn't "teach" you how to play. It should simply exist as a world, and its rules, and you'll figure out the rest. Incentivized to explore particular areas of the world/rules, but thats about it. Bad design comes from limiting your ability to explore. Rules that appear general (applies to all NPCS), but it turns out you can't punch the kids, because. You can normally jump around as much as you want...but this particular area you have to sit down and walk because its movie-time. You can run around as much as you wish, but here there's an invisible wall because you're not at the designated level for it. Or the lack of things to explore. Poorly designed procedural generation games like No Man's Sky and Borderlands come to mind. The generation rules constantly produce different/new things... with little difference to your actual ability to interact with the world. It gets boring, fast, because it's not affecting the ruleset to any interesting degree. But a proper roguelike on the other-hand has you forced to explore corner cases of the ruleset every time you find a new enemy with some special combination of [dangerous] skills. The roguelike ruleset is potentially interesting (and expansive), and the procedural generation pushes you to explore all its corners. No Man's Sky has a much more limited ruleset, and the generation leads you to explore all its corners... very, very quickly. And then ofc you have other aspects like compositional rules and feedback loops that allow the player a much freer exploration, of the world, to the point that you have genres defined around it (eg simulations, grand strategies, etc).