*dons flame proof hazmat … hopefully no holes*

I love deep interesting companions with relationships and romances! There I said it.

Beyond that what Ripper said.

Plus deep lore, interesting world to explore, non-linear (as much as a story can allow), a freedom to make your own character versus having a very strictly defined one thrust on you - the more choice and freedom the better.

Oh and an animal companion is always a personal plus in my book :)

Action-RPGs really don't need much of an interesting setting, if the goal is to drive the player with loot as carrot-on-a-stick.

Blizzard was imho very bad at worldbuilding, their world design of their first 2 Action-RPGs (which i had been playing somewhat around 2 decades ago) felt like they could fit on one sheet of paper.

They actually needed novels to expand that, but the world itself - nothing.
Their first Action-RPG is basically nothing but a Roguelike. Once I had discovered that it had oh so many similarities with Nethack (the first Roguelike i ever knew), only much, much darker, like the cover of an heavy metal album, its magic was gone.

The "problem" with LOTR is basically that it is a fully non-action book. It fits so much NOT into the current landscape of action-filled media that I doubt that youngsters will like it. It basically reads like a Reiseroman. Basically the description of a journey - and that by foot ! - Mostly, at least.

I … guess … that a developer must decide for what kind of audience the game is made for. Depth ? Or carrot-on-a-stick aka loot games (after the Blizzard formula) ?

I haven't seen yet a game which manages to combine both.

Besides, as a learning course I advice to at least take a look at the game-satire called "ProgressQuest". https://en.wikipedia.org/wiki/Progress_Quest