I was genuinely taken back by how gorgeous Stella looks, and the ending with the prelude music and the nod about development, might be sad, but, that was slightly emotional lol.
At first I was sad to learn the great Nobuo Uematsu wasn't composing for XV (I didn't actually realise until recently) but the music throughout that trailer was fantastic, set up the vibe instantly.
Some of the negative comments I don't really understand, the whole because they are wearing black = group of emo guys? What? I believe the costumes aren't even Squares designs and are designed by a fashion label/co-designed.
Not sure why people find a giant Adamantoise or a Car in Final Fantasy "odd" either, I mean each to their own, but I'm not sure how much attention you've paid to the series. I can understand if you don't like the art style, but the art style and graphics aren't the same thing, graphically it looks great (Minus missing some chunks of polish of course, but this isn't exactly a launch trailer)
I'm actually not totally convinced on ARPG's, I enjoy them, but I'm set in my old turn based ways, regardless of that, this is a day one with zero doubts.
EDIT: As Vire pointed out above, I'm wondering how they will handle car physics also if it's an integral part of the game, will they go the extra mile with it or not?