http://www.polygon.com/2017/3/11/14892918/watch-final-fantasy-15-episode-gladiolus-preview-video
"Sawatari, speaking through a translator at this year’s PAX East in Boston, told us that
Episode Gladiolus would be about one and a half to two hours in length.
Once completed, multiple new game modes will open up, including a score attack mode where players will work to get the highest score and unlock additional rewards.
And yes, there are things that can be earned by succeeding in the DLC, but for now Sawatari is being tight-lipped about what they are."
“He has kind of this self reflection moment where he thinks, ‘I’m not strong enough. I’m not good enough,’” Sawatari said. “
There’s this ruin that was discovered about 30 years prior to the main story, where previous Crownguards and shields of the king undergo this trial. And he decided that he needed to go through this to get the power he needed to be the rightful protector of the chosen king.”
nice that they tied the trial to his family legacy, like i imagined.
the lenght will probably be more than 2 hours if you count the other game modes the dlc offers.