About those concepts...
Worldbuilding. Do you mean physical world building or conceptual? Because, while ff13 had no physical change or progression in the world in one respect, it had the second in spades. The game did gradually reveal new ideas, concepts,and stories about the world, which built your perception of it. It's true that it had no real physical exploration, but mental it did have. In that respect: can you really say it is non existant?
Truthfully I feel like that's trading away gold and getting feathers, but others could feel differently and be justified.
Gameplay. Well, there is gameplay in setting up your deck and selecting your roles, and it's true that this is radically different from before, but really it's the same as above. Explority gameplay simply does not exist, but strategic combat gameplay does. Personally, I don't think it's enough to hang the game on, but it is there.
What I think happened was square focused on some aspects of what makes an FF title, while ignoring others. This leads to what feels like a half assed, incomplete game. The problem is, that's a judgement we will never be able to prove. Square could argue that this was their intent and focus all along, and that this is the result of them streamlining the experience into a very direct story. If that was the gameplay they were trying to achieve.
At the end of the day though, whatever type of game they did make, I didn't enjoy it, and apparently I'm not in the minority. I do think it's unfair to say it's a tech demo or not a game. It's just not all that great of a game.
It is one hell of a light show though.
The problem with conceptual world-building is that it's... well, cheap. Lots of people have all kinds of neat ideas, but getting them from paper to product? It often falls through. The fact is that the only world-building a player is going to experience is what you craft in the game. Leaving it up in the air just isn't worth anything to anyone. There are a lot of "idea" guys in the industry, but they can't just be idea guys. They need to know how to go from concept to craft, and they have to do it well.
It's the difference between Cloud in FFVII and Lightning in FFXIII. Both have the attitude, the one-liners, and the looks. But the major difference is that Cloud goes through extensive trauma and comes out a changed person. That just doesn't happen to Lightning, and while she softens as the game goes on, there's no real development. On top of that, she never really stops being the one-note "badass" girl. Cloud becomes more rounded and fleshed out. He grows.
Both are characters grown out of the same concept. The difference is that one becomes a human being as we follow his story. The other remains a caricature, shallow and empty. One exemplifies good character building, which is deeply integral to world-building. The other? Well, she's reflective of her world as well.
Concepts are cheap. Actual quality products with developed worlds and characters, worth buying, owning, and treasuring for the memories they give us? They can be priceless.
Gameplay has to do with how the game actually integrates narrative, characterisation, as well as regular functions that the player inputs.
Narrative that doesn't arise from gameplay is irrelevant to gameplay.
I think we agree on this point. It's the developer's responsibility to take narrative and work it into the gameplay. Lost Odyssey's memory sequences, for example. They're... gorgeous. The writing can really touch you, and it's a shame it isn't more prevalent throughout the game. It's a stellar example of where narrative, largely independent of gameplay, is one of the best aspects. That said, it's deeply irrelevant, because it isn't
integrated with the game. The same is true of Xenogears, which has a really compelling narrative, world-building, and cast of characters. The wholesale problem is that the gameplay isn't well-integrated after the first disc.