[Game Design] What Makes a Zelda Game So Special?

Any game designer could identify good aesthetics, music, initial leverage on popular consoles, great marketing, high replayability, exploration design, and the flow challenge of puzzles. But there are other behavioral details, I found, that help make The Legend of Zelda games so popular across generations.

I decided to follow up on a Quora thread on this, and decided it would be cool to post my thoughts here. 
These are factors that were cleverly replicated and built upon along the series, creating a sense of "what a Zelda should feel like". This creates a craving that repeats itself over approximately two year cycles, feeding on the game development genius that is Nintendo:

1. The story of personal growth in responsible use of power, collection of wisdom through solving "puzzles", and embracing courage facing your fears against "monsters".
2. The feeling of nostalgia, and growing with the franchise. Old games were ridiculously difficult and forced players into checking every little detail both in the story of the virtual worlds and in the places you would visit. Some of these were carried along the franchise as fan service for old players, giving fans some bait while also appealing to new players.
3. Sense of emotional accomplishment and reward, through helping people on main and side quests, acquiring badges, small tweaks to the character, or even exploring every nook and cranny for easter eggs. This appeases both completionists as well as gamers who are more interested in the story.
4. A timeline, or meta story, which always leaves room for mistery and speculation. It is now known that all Zelda games are connected and happen in the same universe. Nintendo creatives purposely design leaving room for fan discussion after finishing every game, giving players hints into a much deeper story. This led to an aspect of mystery within the fandom that keeps them wanting more, thus inducing consumers into buying the next big franchise installment. This strategy is also used across other Nintendo games such as Star Fox and Metroid.

¿What do you think? There sure can be more stuff, but I feel Nintendo is always aiming at making meaning through their games, and teaching players lessons in one way or another. Always aiming at the higher brain and not only emotion or instinct based gaming. This goes a bit farther in Zelda like games than in other game types or franchises.