I was just at Gamescom and I heard more new info about the story, which I think it wasn't already said.
There are several meteorites that crashed on the planet and I think he said Niflheim is the one, who absorbs the energy of them.
Than I instandly thought it would be like in FF VII. O_O
Shinra absorbed the Mako-energy for their needs, but instead the planet was going to die.
So I think these meteorites in FF XV are like the one in the Demo of Duscae, where Titan ''sleeps'' there.
And Niflheim steals this energy to gain special power for most possibly the war and the meteorite/Titan dies.
Perhaps that's the reason why there was an earthquake in that location and Noctis and his friends are going to the Titan to search the reason behind this, but Titan is in rage and attacks them, so they have to absorb him to destroy Niflheim.
The other info is an artwork, which I forgot to take a photo -,-
This one wasn't shown either if I'm not wrong.
The artwork looked like the Grand Canyon in the USA, which looked really beautiful, but in the distance you could see some big rocks that floated over the canyons and one of this pillar rocks like in the Duscae region.
All in all it was a mix between reality and fantasy. It looked really cool and real.
There was also one artwork of Cindy and behind her was I think a factory or a workshop, but I think there was also a plane and an aircraft hangar.
Also one about Lestallum.
Damn, now where I think about these artworks, I regret that I didn't took photos xD
BTW the one artwork with aerial fight next to a skyscaper this thing was a monster with red, yellow wings and a beak.
Hope this is also in the final game