What games have what you’d call really good worldbuilding, and what in particular do you like about them?
https://en.wikipedia.org/wiki/Worldbuilding
Worldbuilding is the process of constructing an imaginary world or setting, sometimes associated with a fictional universe. Developing the world with coherent qualities such as a history, geography, culture and ecology is a key task for many science fiction or fantasy writers. Worldbuilding often involves the creation of geography, a backstory, flora, fauna, inhabitants, technology, and often if writing speculative fiction, different peoples. This may include social customs as well as invented languages (often called conlangs) for the world.
I want to answer Xenogears because of all of its story and storytelling, but the worldbuilding itself is kinda standard, if not for the scope of it. You do end up learning about pretty much everything there is to learn - the world and its history, the characters and what moves them, the politics, the conflicts, the geography, the physics, the religions, the supernatural, the origins of mankind - not to mention a full class on philosophy. And then whatever question you still have left, there’s a book about it in addition to the game.
And you start with a classic amnesiac character in a small village.