Somebody on the internet translated the menus of the FFXV demo showcased on that stream, so we can have a better understanding of the weapons and abilities and whatnot. I'll post some of the images here, then you go to the source to check the rest and the gifs.

This one because it has a Jump, which is always awesome.

Anyway. the rest of the screenshots and the gifs are on this site: http://www.dualshockers.com/2015/02/22/final-fantasy-xv-translated-screenshots-and-animated-gif-show-noctis-weapons-and-his-attacks/

Also, here's an estimate of the size of the demo's map, and a sort of educated guess of the size of the full game's map (thanks HollyGamer): http://www.dualshockers.com/2015/02/21/final-fantasy-xvs-episode-duscaes-map-size-1-16-square-miles-8-of-skyrims-map-size/

Jesus Christ, that Wyvern Spear sounds OP as fuck. :P

It most likely is a mix of both. I imagine it being similar to Final Fantasy XII, it can be as easy or as hard as you want it to be. 

One thing to notice is that you apparently can change you party equipment, as opposed to them being completely out of your reach.

You... you herectic! What a shit taste.

No, but seriously, what did you hate about it?

Yeah its looking super casual atm. Attack an defence? what about all the other attributes?

Everything? I'd say that's strange, since the battle system is not that different from the ATB in previous games (imo). Just with no random battles.

OP please add this link about map estimation as well : http://www.dualshockers.com/2015/02/21/final-fantasy-xvs-episode-duscaes-map-size-1-16-square-miles-8-of-skyrims-map-size/

I don't mean that it would be exactly like it, but I imagine it being moving away from X to win that was sort of present in 13. I imagine they want you to have teamwork in battles in this one. Similar to Final Fantasy 12. 

Thanks, will add it.

I don't like this menu... But that's ok. :S